Most of my friends are gamers as it were, and though we do play a lot of console and PC games, it is always so much more satisfying to play a board game.
In list form, some of the ones that I play regularly:
Scrabble - classic
Heroscape - since we have nearly all the expansions, this can be the most epic game
Risk - another classic
Settlers of Catan - good game, though there are other games in a similar vein that I prefer
Puerto Rico - number 1 on boardgamegeek.com for good reason
Epic Duels - Star Wars based where you pick characters and have them battle it out based on their deck of cards
Trivial Pursuit - so many versions, and the best trivia game ever
Wit's End - more trivia, though generally more difficult that trivial pursuit
Then we have other classics like Monopoly which can be fun to bust out now and again. And since I am a hardcore geek, I've dabbled in D&D in the past, and will probably be getting into the new 4th edition rules once we all familiarize ourselves with it.
If you're unfamiliar with any of these, you can check them out at Board Game Geek. I would recommend them all.
So what are your favorite board games?