Spelunking

When Spelunking enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.

Gateway Plaza

Gateway Plaza enters tapped.
When Gateway Plaza enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

Forest

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.

Thran Portal

Thran Portal enters tapped unless you control two or fewer other lands.
As Thran Portal enters, choose a basic land type.
Thran Portal is the chosen type in addition to its other types.
Mana abilities of Thran Portal cost an additional 1 life to activate.

Golgari Guildgate

This land enters tapped.
{T}: Add {B} or {G}.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Llanowar Elves

Selesnya Guildgate

This land enters tapped.
{T}: Add {G} or {W}.

Maze's End

This land enters tapped.
{T}: Add {C}.
{3}, {T}, Return this land to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Dryad of the Ilysian Grove

You may play an additional land on each of your turns.
Lands you control are every basic land type in addition to their other types.

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Rakdos Guildgate

This land enters tapped.
{T}: Add {B} or {R}.

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Orzhov Guildgate

This land enters tapped.
{T}: Add {W} or {B}.

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Aftermath Analyst

When Aftermath Analyst enters, mill three cards.
{3}{G}, Sacrifice Aftermath Analyst: Return all land cards from your graveyard to the battlefield tapped.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.