Inspired by the main villain thread, how about the guys who prop up their bosses and make their nightmarish ideas realities? In no particular order, I'd say my top 5 from the decade would be:
-Tot. I don't even want to consider what his parents might have possibly done to him to make him a diseased maniac. His understated way of going about his business makes him seem even more sinister.
-Karl. His strong violent actions are the perfect contrast to the more calculated moves Gruber makes. There is some serious doubt whether McClane can stop him once he gets into total rage mode
-the Terror Dogs. Even the character design invokes real fear. They're relentless in pursuit and swift in bringing down the people they're after
-Bob the Joker's main man. He shares his boss's sick sense of pleasure in hurting people. Too bad Batman never did get a chance to square off one-on-one with him; that would have been a nice showdown to see
-Flotsam and Jetsam. I rate only Iago and Diablo the raven higher among the company's many memorable henchcharacters. These two are good contrasts to their mistress, playing openly slimy to her more legitimate act. They're also thoroughly competent, in contrast to many other animated henchpeople, and are quite capable of causing great damage on their own, and thus more than deserve their final fate.