The best video game monsters / bad guys

The very first Goomba in Super Mario Bro's. He probably has the highest kill count of any enemy ever. 
That's not to say his kill/death ratio is any good however.

I like killing Grunts, they say some pretty weird things and i like how they run away from your once you kill there Elite or Brute leader. Plus with the confetti skull turned on, it gets so much better.

    Now, Im not talking about a boss characters, but if you think one of them deserves your vote, then so be it.   "

I'd almost immediatly say Big daddy's, well the bouncers anyway. Metropolitan Police are probably better though. They are organised and show dominance. 
 
Untill you get better weapons of course.

I'm not really sure how to classify him, but I would suggest Hogger from World or Warcraft.  He's basically the first elite you meet in the Alliance starting zone.  A bit of a pain in the ass if you are a noob and soloing.  Memorable, though.

All the random goons from God Hand. Why? Because God Hand is one of the few games where the random nameless enemies you face are a significant threat.

Stupid french people in Broken sword.

Another great, clasic monster / bad guy, would have to be the Resident Evil zombie. Granted they were stupid, moved verry slowly, and the low quality sounds used for the zombie growl made them seem even less threatening. But the first time you saw those things, and you shot them a couple of times, and they still went afther you, gave you a verry wierd feeling. 

  
 
 
 
 Since gaming keeps evolving, and better tech allows for games to be faster and more action - e,   they had to change this enemy in to the Resident Evil 4

 villager. Those dudes were fast. You were used to the slow moving zombies, and out of no where, the new enemies could talk shit, surround you, navigate the environment. Andthe chainsaw wielding guy. My gosh, the chainsaw guys took a bunch of bullets and they still went after you. That sound the chainsaw made when they were chasing you, ment that you had to run like heck. Eventually people figured out how to deal with this guys, but that first encounter with them, it sure was something.