Backgammon is my favorite board game however I like cards. You name it, pinochle, euchre, poker, hearts, spades.....

Four different games that deserve a mention:

1: Colonists of Catan. I've got so much history with this excellent board game that it actually feels like the other way around.

2: Chess: I don't play it very often due to time and concentration required, but if I do it's priceless!

3: Poker Texas Hold'm. The best regular card game out there. It's got all: excitement, anticipation, tactics, bluffing, outsmarting and sheer luck. Sucks when your drunk, money wise, but excellent when the others are drunk .

4: Dungeons&Dragons. The geek in me loves this game. It's the most free, most fantastic, most mentally challenging game out there. I do play it with a group of friends every now and then, but not often. Though a life changing experience when first played. Forget LotR or WoW: this is the real thing.

Edit: maybe just for the sake of it, but both Risk and Cluedo deserve a mention too.

You can make almost any board game into a sex game by using your imagination. My favorite is checkers and Monopoly