It's really going to depend on your group of players. There's a wide variety of board and card games available with different mechanics and play styles.

I can recommend Race for the Galaxy:

http://boardgamegeek.com/boardgame/28143/race-for-the-galaxy

Browse around the BGG website, read reviews, look at the top games, etc:

http://boardgamegeek.com/browse/boardgame