The old white Easton XL1! I think it was the first version of the XL1. It is a rocket launcher. But the issue is that they don't last. The barrel wobble is so common with these bats. We have had 4 of them in the past year and a half. 3 of them ended up with the wobble. I am just waiting on the last one we have to have the same issue. We played mostly wood tournaments this summer. Our last tournament was metal bats. I brought the XL1 to batting practice and the kids were shocked by the bat. Half the team ended up using it in the game.
I also still think the black/yellow Easton S1 is an all time great.
For most recent bats:
The Goods
Red Meta Prime
Blue Meta
Rawlings Quatro (green barrel with black handle and the all black version)
As you can tell, my son likes swinging 2 or 3 piece bats.