Dominion is a very unique game. It's a card game, but instead of having a deck that everyone draws from, each player has their own personal deck that they build up by buying cards, the point of the game being to build the most efficient deck possible in order to buy the most Victory Cards before the game ends. On your turn, you draw 5 cards, play any action cards from your hand that you want to, and buy 1 card, using treasure cards from your hand. You then discard everything you didn't use and draw a new hand from your deck. Action cards-which you don't start with, you must buy them and wait for them to shuffle back to you in your deck-do a variety of things, but mostly add on to the basics of what you can do, such as buying a larger number of cards, being able to play more action cards, or just giving you more treasure for this turn.
What the heck, I'm just going to make a Pros and Cons thing and have done with it.
Pros:
An insane amount of replayability
Well-designed
Moves quickly, as you can plan your turn during others' turns
Medium amount of complexity, fits everyone well
Cons:
Some kooky art amidst the awesome, including completely different styles
Small amount of player interaction
Officially only 2-4 players (Dominion: Intrigue, a stand-alone game, adds official rules for up to 6)
One of the best games I've played.