Cards Against Humanity isn't just a game, it's a game-changer. The low-budget, open-source, gross-as-all-hell multiplayer experience has led to a lot of copycats, but this one looks like it could really work.
Bad Words, the debut product from Hosnovan Co (aka four friends who want to quit their jobs), combines the sense of humour of Words Against Humanity with the gameplay of Taboo. Can you describe the thing at the top of the card without using any of the forbidden words on it? It's like describing the city of Lima without being able to say "Peru", except with a lot more butts, poo and genitals.
In this case, for instance, you'd have to say something like "An occasional and extremely unfortunate side effect of beta-blockers" until they got what you were talking about. Fun, upsetting stuff.
There are plans for numerous expansion packs, different game modes, and whole new world of filth if the project's Kickstarter gets fully funded.
If you like games, swearing, and filth, get involved!