I'd love an SA Asajj in the above Season 3 outfit, finally with elbows, etc.
Fives and Echo were obvious choices. Random ARC Troopers sell like hotcakes, releasing two super-cool significant characters in their ARC outfit would've been printing money.
How about Bo Katan, or Tarkin? An updated Pre Vizsla with the new armor deco and helmet? Not to mention the many easy and awesome repaints that could have been for both clones and droids. Where are all the named Phase II clones from Umbara? And how did they never release a single repaint of R2's battle droid squad from the Citadel episodes?! Especially now that they have the droid legs with knees from the bike set and the updated arms from the 2013 BDs...could be some of the nicer battle droids.