I don't have all the ones I'm after yet, but of the ones I do have (all acquired as an adult btw) I have to give it to Ramulus.

I totally dig TM2 Dinobot as a concept/in theory (biomechanical, undead velociraptor...sure, sign me up!), and I really did/do like the toys in general, but as a toy Ramulus is really good. If they'd made his head more poseable in beast mode he'd be even better, but he's still a solid toy with interesting design elements.

I would have voted Dinobot, except his toy really isn't all that good. Pity...it was a cool design.