I would have to say Chewie Mechanic. I bought like six of them: one for my Bespin escape group (BTW he looks coolest with the pull apart Threepio on his back and Leia's spare blaster.), one to replace the crappy Mynock hunt figure (which is where one of my POTJ Hans is also, and yes the mask fits), one for my Cantina set-up, one with my Falcon (the only time I actually use the accesories he came with.) and some extras in case I come up with a cool display idea.
Next to him I would say Bespin capture Han, Duro, Lando and Bespin escape Leia.
As for upcoming fugures, I'm really looking forward to Luke X-wing, Han Death Star escape, FX-7, Luke Bacta, Amanaman, and the Imperial Officer.
Oh yeah and Ephant Mon.