Captain Storm, Cosmium Raider

Whenever an artifact you control enters, put a +1/+1 counter on target Pirate you control.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Toggo, Goblin Weaponsmith

Landfall — Whenever a land you control enters, create a colorless Equipment artifact token named Rock with "Equipped creature has '{1}, {T}, Sacrifice Rock: This creature deals 2 damage to any target'" and equip {1}.
Partner (You can have two commanders if both have partner.)

Dargo, the Shipwrecker

As an additional cost to cast this spell, you may sacrifice any number of artifacts and/or creatures. This spell costs {2} less to cast for each permanent sacrificed this way and {2} less to cast for each other artifact or creature you've sacrificed this turn.
Trample
Partner (You can have two commanders if both have partner.)

Arcane Signet

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

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.)

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Sol Ring

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Goblin Kaboomist

At the beginning of your upkeep, create a colorless artifact token named Land Mine with "{R}, Sacrifice this artifact: This artifact deals 2 damage to target attacking creature without flying." Then flip a coin. If you lose the flip, Goblin Kaboomist deals 2 damage to itself.

March of the Machines

Each noncreature artifact is an artifact creature with power and toughness each equal to its mana value. (Equipment that's a creature can't equip a creature.)