Kind of a tough one, as I'm looking forward to a lot this year. This looks like it could be one of the best all-around years for collecting yet (and most expensive). Anyways, if I look at it from the aspect of "if I could only afford to buy the minimum, what would make the cut", my top two priorities - if I couldn't buy anything else - would be:
VTAC Collection (Hoth Han, Bespin Luke, Endor Leia, Snowtrooper, IG-88, Bossk)
McQuarrie Concept Figures
Other than that, from what we have seen/confirmed, I'm looking forward to these as well:
Jawa w/LIN Droid
Luke Skywalker (Jedi)
Boba Fett (Animated)
I'm pretty much looking forward to all of the figures this year, particularly the OT ones, and also many of the ones that have been rumored so far (Bespin Han, Smuggler Lando, Yoda w/Kybuck, Roron Corobb, etc.) Its going to be a good year.