How big a group are we talking about? It makes a difference.
One party game I enjoyed was called "What if?"
The premise is simple. Everyone takes a piece of paper and writes a what if question, for instance:
Example 1:
What if what ever you touched turned to chocolate?
Example 2:
What if you were a zombie?
They then fold them in half and put them in a jar or bucket, the papers are then mixed up and passed around, and people answer the ones they recieve. So you'd get something like:
Answer to Example 1:
I'd be very fat.
Answer to Example 2:
I'd lay waste to all before me.
You then have everyone sit in a circle (or have them sit before this point), mix them up again and have one person read the question on the piece of paper they have, the person next to them then reads the answers to the question they have. Then you alternate until you make your way around the room. You get all sorts of fun wacky stuff. So using the examples I've provided:
Person 1 (reading the question on their slip of paper): What if you were a zombie?
Person 2 (reading the answer on their slip of paper): I would be fat.
Person 2 (reading the question on their slip of paper): What if what ever you touched turned to chocolate?
Person 3 (reading answer on their slip of paper): *answer*
Person 3 (Reading question): *question*
Person 4: *answer*
You then continue around the circle until the person on the other side of the Person 1 reads their question and then Person 1 reads their answer (I would lay waste to all that was before me in response to what ever the question is Person X had).
I'm probably not explaining it very well but after the first round people get the gist of it and write the wackiest answers and questions they can think of the maximize the humor value. You may need to caution to keep it clean but it is a hoot, a lot more fun then I'm probably making it sound.
There, now you know at least one party game.