Ju Jitsu. I'm doing it 8 years straight.
My favourite move would be the o uchi gari.
It's basicly when you grab one foot (catching a kick) and you sweep away the other one, lift him up, and smash his back (or the back of his head) to the ground.
What I also like is the full roundhouse headkick. I've been practicing this for a fairly long time now, did it in a couple spars, it's a great way to end a combo, for example:
Jab-jab-hook-hop back-roundhouse.