Favorite Board game of all time?

I grew up loving board games and card games. I'm back on a kick of buying board games and wanted to know if there were any must gets?

I haven't played it, but everyone says Settlers of Catan is a must get. I grew up playing Conquest of the Empire and Risk, but my wife doesn't like those long strategy games so we play games like Scrabble or Taboo if we're playing any board game. I find Risk, Monopoly and other wildly popular games to take way too long to play often enough. Games like Trivial pursuit just seem to make me feel really dumb for not knowing who the UN amassador of the US was in 1987.

I stumbled onto this game recently, looks like a lot of fun:
Cards Against Humanity
Anyone here played it? I've played some rather nerdy card games in my youth, but this looks like it could be a lot of fun.