Gygor! He adds so much to a display. Towers over the other figures, looks incredible, and did I mention that he's a huge gorilla with a giant axe? Everything about Gygor screams 'awesome.'
I was tempted to vote for Adora, but did not. I feel that she's integral to a MOTU display, as much as Adam is. She's IMPORTANT, but in no way (and this is ONLY my opinion) a nice figure. Mine has messed up legs so she can't stand well, first of all. But more importantly, she's boring. I just find her to be a fairly unappealing figure. More a necessity for my collection than a figure I really enjoy owning (like Gygor).
Wun-Dar would have gotten second place for me if I'd voted for more than one figure. The fact that he even GOT a figure is pretty cool. And I like that Mattel attempted to incorporate him into the mythos while still doing little nods to his origin, like the WunDarBred logo on his armour.