This is hard to say...
I will be getting my first Prime 1 and my first XM piece this year (both Wonder Woman) so that is really exciting.
I guess the one I think about the most right now is DC Collectibles Bombshell Big Barda because Entertainment Earth still hasn't shipped mine and I've seen it at my local shop so makes it really hard waiting.
The whole Tweeterhead Super Power line has so much possibility with Donna Troy and other oft ignored characters getting a shot.
Of course the grail of grails in the back of my mind is that Power Girl in the Prime 1 Artgerm 1:3 series as already have Supergirl and Mera pre-ordered.