This is hard actually because going off looks i want fett at the top; however he did next to nothing in the actual movies. Fett did have major action in the comics though so I think I want to put him at the top.
Next would have to be the ig series droids. From what I remember they were all bounty hunters and as one goes offline another comes on or something like that. Maybe should lump the c3px in there also as he was an assassin bounty hunter droid type character also if my memory serves me right. So I guess for number two i am gonna make a broad range and say droids that are bounty hunters.
Thirdly, just because fett is so high in my awesome category I kind of want to include jodo kast. He was a fett look alike and was just as good as fett until the two fought each other.
Honorable mention can go to any others really. They all have rich history and back stories in the comic realm even if they are unknown to the movie side. There are a lot more than we have named yet though. Thinking bossk, 4lom, zuckus, cad bane (know nothing other than this guys name), aurra sing, greedo, boush, the wookie one Chewbacca dresses as in shadows of empire, etc..