Im going to have to go with Megatron here. Simple transformation but he is so show accurate and this Megatron was an awesome design in the show. Also one of the best Megatron's in any continuity. I seriously didn't know if Decepticons were evil in Animated cuz of Megatrons speeches.
I'd have to say Megatron. A solid figure and the closest we have come to G1 Megatron. Plus it made up for the lack luster Voyager. Still disappointed about picking that one up. I'm a bit bias as I never bought Magnus. A good figure no doubt. But I've been trying to cut back on spending.
Write in for Bulkhead. Hell he looks great is fun to transform and has the gimmick of a backpack chair even like we saw in the show.
