Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Krark's Thumb

If you would flip a coin, instead flip two coins and ignore one.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Mind's Desire

Shuffle your library. Then exile the top card of your library. Until end of turn, you may play that card without paying its mana cost.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Harmonic Prodigy

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If an ability of a Shaman or another Wizard you control triggers, that ability triggers an additional time.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Harnfel, Horn of Bounty

Discard a card: Exile the top two cards of your library. You may play those cards this turn.

Birgi, God of Storytelling

Whenever you cast a spell, add {R}. Until end of turn, you don't lose this mana as steps and phases end.
Creatures you control can boast twice during each of your turns rather than once.

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Imperial Recruiter

When Imperial Recruiter enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Mountain

Sol Ring

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Brightstone Ritual

Add {R} for each Goblin on the battlefield.

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Overmaster

The next instant or sorcery spell you cast this turn can't be countered.
Draw a card.

Command Tower

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Dualcaster Mage

Flash
When Dualcaster Mage enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Spellseeker

When Spellseeker enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

Strike It Rich

Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Heat Shimmer

Create a token that's a copy of target creature, except it has haste and "At the beginning of the end step, exile this permanent."

Twinflame

Strive — This spell costs {2}{R} more to cast for each target beyond the first.
Choose any number of target creatures you control. For each of them, create a token that's a copy of that creature, except it has haste. Exile those tokens at the beginning of the next end step.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Phantasmal Image

You may have Phantasmal Image enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Step Through

Return two target creatures to their owners' hands.
Wizardcycling {2} ({2}, Discard this card: Search your library for a Wizard card, reveal it, put it into your hand, then shuffle.)

Submerge

If an opponent controls a Forest and you control an Island, you may cast this spell without paying its mana cost.
Put target creature on top of its owner's library.

Tavern Scoundrel

Whenever you win a coin flip, create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")
{1}, {T}, Sacrifice another permanent: Flip a coin.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Ragavan, Nimble Pilferer

Whenever Ragavan, Nimble Pilferer deals combat damage to a player, create a Treasure token and exile the top card of that player's library. Until end of turn, you may cast that card.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Finale of Promise

You may cast up to one target instant card and/or up to one target sorcery card from your graveyard each with mana value X or less without paying their mana costs. If a spell cast this way would be put into your graveyard, exile it instead. If X is 10 or more, copy each of those spells twice. You may choose new targets for the copies.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Fiery Islet

{T}, Pay 1 life: Add {U} or {R}.
{1}, {T}, Sacrifice Fiery Islet: Draw a card.

Rite of Flame

Add {R}{R}, then add {R} for each card named Rite of Flame in each graveyard.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Island

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Peek

Look at target player's hand.
Draw a card.

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.

Void Snare

Return target nonland permanent to its owner's hand.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Mogg Salvage

If an opponent controls an Island and you control a Mountain, you may cast this spell without paying its mana cost.
Destroy target artifact.

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

Krark, the Thumbless

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Pyretic Ritual

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Desperate Ritual

Add {R}{R}{R}.
Splice onto Arcane {1}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)