I think flirting is great fun. It doesn't mean that anything's going to come of it but it's fun to be told that you're hot and that your tits look great. You all get your pens out.
My favorite time to dance is at, like, wedding receptions, when it's all ages and everyone seems to be having fun.
I enjoy darker sardonic wit more than knock-knock jokes. I spent the first healthy chunk of my career playing all-American, pleasant, average, nice people, so it's fun to have some complications there.
It's like, the more you commit, the happier the animators are; if you're at all iffy and concerned, then it doesn't free them up to do as much fun stuff, so you have to just go for it and, again, trust the people around you and not be seemingly guarded and numb. Throw caution to the wind a bit.
I'm a games and theory kind of guy. I love puzzles, so it was fun dissecting Shakespeare's prose.
Starship Troopers was great. It was great fun to work on something with blue screens and big budget special effects. Denise Richards was nice to look at too, of course.
Playing a villain was fun, only because you get to do all the things you wouldn't normally do in your real life.