So tough for me to say which is my most favorite but i will throw a few out that I love.
Jawa (still my favorite Jawa figure, the new ones are great but just dont have the same appeal)
Wicket (the modern line has yet to capture him)
Yoda (again, i still think the vintage one tops the modern versions)
Kybuck (I think this pack-in was just awesome)
Amanin (from the comic pack)
Salacious Crumb (pack-in from C-3PO)
Ewoks (the newest modern ewoks are just incredible and i can't wait for Wicket to finally be redone)