Yes, there are a number of Magic: The Gathering cards that say "you win the game."

Of course, they'll all make you jump through some serious hoops. They also function in various ways. Let's take a brief look at the history of this phrase as it exists on cards, then go through some of the more common options and how they work.

Where it all Began

The first card with the words "you win the game" was The Cheese Stands Alone, from the 1998 set Unglued.

The Cheese Stands Alone is a Enchantment that says that if you control no other cards on the Battlefield and have no cards in your Hand, you win the game.

There are a couple of things to note about this. The first is that the win occurs as a state-based action. If you control The Cheese Stands Alone and you manage to achieve the board state it requires (zero other Permanents and an empty Hand) then you win when the game checks the board state, which is any time priority would be passed.

This requires a fair bit of planning, however.

Additionally, cards from Unglued don't really appear outside of casual formats. So, you probably won't encounter this, even from the goofiest deckbuilder at your local Commander night.

When it Got Real

October 2000's Invasion brought the first tournament-legal "you win the game" card: Coalition Victory.

Coalition Victory is a Sorcery that says you win the game if you have a Land of each Basic Land type and a Creature of each color.

Because it's a Sorcery, Coalition Victory wins when the spell resolves if all the conditions were met. It's not as simple as being able to create every color of mana: you must have one of each Basic Land type.

That said, if you have a Land that's more than one Basic Land type (something that says "Swamp Forest," for example), that will count as all named types as far as Coalition Victory is concerned, so you can meet this condition with as few as two Lands.

This was a serious enough problem that it was banned in Commander for a while, but at the time of writing, it is legal again.

The next one was from 2002's Torment. It was called Mortal Combat.

Mortal Combat is an Enchantment that costs which says if you have 20 or more Creature cards in your Graveyard at the beginning of your Upkeep, you win the game.

This is substantially easier to achieve than Coalition Victory. It is a Triggered Ability, which means it goes on the Stack at the beginning of your Upkeep. If you have at least 20 Creatures in your 'yard when it resolves, you win. It has never been banned.

What else is there?

The most common options in Commander, especially in cEDH, are Thassa's Oracle for and Laboratory Maniac for .

Thassa's Oracle

Thassa's Oracle is a Blue Creature that lets you look at the top X cards of your Library when it enters, where X is your Devotion to Blue.

Devotion is a mechanic that cares about the number of specific mana symbols that you have on Permanents you control.

If X is greater than the number of cards in your Library, then you win.

Laboratory Maniac

Laboratory Maniac, on the other hand, says if you are supposed to draw a card and can't because there are no cards left in your Library, you win the game.

Doctor Doom, Unrivaled

The latest version of a "you win the game" card is Doctor Doom, Unrivaled.

You may tap this 4/4 Creature to draw a card and lose a life. If you draw the last card of your Library (or if you have no cards in your Library when you activate the ability), then you win the game.

Felidar Sovereign and Test of Endurance both care about how much life you have: if you have the amount it says on the card (40 and 30, respectively) at the beginning of your Upkeep, then you win. Whereas Near-Death Experience cares if you have exactly one life.

Hellkite Tyrant and Knuckles the Echidna both care about the number of Artifacts in play. If you control a certain amount of Artifacts at the beginning of your Upkeep, then you win the game.

There is also Battle of Wits, a five-drop Blue Enchantment which says that if you have 200 or more cards in your Library at the beginning of your Upkeep, you win the game.

Final Answer

There are several MTG cards which say, "you win the game." Each one requires a specific set of conditions to be met in order to succeed. However, with proper planning and a lot of luck, you can pull off a fun win condition.