The basic rules are like the game Apples to Apples, but it's got a more evil twist as it is meant just to be funny. On the plus side, you can print it out yourself via pdf printing at your local Staples.
played a game called "Grave Robbers From Outer Space" recently. you create your own sci-fi/horror b-movie and use it to attack other players' movies. you use creatures like "tentacles" and "masked killer" and special effects and characters to make the best movie out there. gets pretty funny with all the b-movie references and what not. definitely worth a play
A good number of Steve Jackson games are funny (Chez Geek, Chez Cthulhu, Munchkin, Ninja Burger). I played another card game called Marriage Material that was pretty hilarious. It's all about evading marriage, though, so if you take relationships too seriously, it might not be fun.
Penny-Arcade: Gamers Vs. Evil is very good, and very funny.
What other game has you actively trying to amass an army of Scrotuum soldiers while attempting to use Pickle Recognition Engines in combination with Touch Weiners for the DS to win the sleighbells of slaying from jolly old Saint Nicholas in order to defeat Satan and take his deadly sins of gaming?
I carry We Didn't Playtest This At All with me in my backpack at all times, especially at midnight openings of games or movies and conventions; it is the only game you can thrust into someone else's hands, and tell them, "Draw a Card, Play a Card. Try to win," and they will just go with it. It's the ultimate time-killer for lines.
I do this all the time, and I meet tons of new people through it.
Our funnier games are usually the filler games while we wait gor someone or to decompress after a longer competitive game. Red Dragon Inn was the goto game for us for almost 2 years. The fluff and color text is great, it's easy to pick up and can be played in 20 minutes. 2nd edition has the best variety of characters though we mix them all in together.
Magical Athelete is stupid, easy fun. Bang can be funny with the right group, Gloom too. King of Tokyo is a quick, fun filler game. Hex Hex is new for us but so far seems like a good choice too.
After watching the episode of Tabletop where they played Say Anything, I had to go out and buy it. I played it last night at a friend's house with his wife and brother-in-law and I have to say it is one of the most fun games I've ever played.
It's similar to Apples to Apples except that each player gets a blank card (dry erase) and can come up with their own answer. As you could probably guess, there are a lot of lewd and rude answers you can put down.