Love My Kids! I showed them my "beautifully rendered" cartoon depicting the SAS congruence postulate, and gave them their assignment. I basically wrote on the back of that cartoon something to the following effect:
1. Pick one of the following thms/posts
2. Create a cartoon, fairytale, soap opera, .... that shows your thm/post
3. Make it neat, accurate, .....
4. Suggestion: pick soon, then mull over your idea since that's the hardest part, THEN tomorrow create it. (we're on block schedule)
We had a discussion about it not looking like it's a last minute haphazard work.
Here are some samples of what I got back. It's a good mix, and I'd say about 90% of my students created something on par with these. I think I partly got good results because it's the 1st week back from break, so they don't have TOO much other homework. Also, I haven't done many "fun" homeworks for these 10th grade geometry students, so that's another potential reason.
This student is also taking French:

This is how she talks, so it's really funny. I freakin' love it:

Love the classroom theme:

Jerry Springer-esque. Hysterical:

Some people went above and beyond:
Holy Cow, a fairy tale in a booklet:

Very Creative: