My favorite combo when I played the Xbox demo was grip, throw my lightsber to impale the guy, lightning, then force push. It was awesome.
On the Wii version my favorite power was probably simply force push, I loved how over the top it was.
My favorite costume is probably heavy training gear, though I like most of them. For lightsaber colors I used red and blue throughout my playthrough and I always used the force push crystal (till the last level I used the improved lightsaber one).