I'd have to go with The Cyberdemon from Doom (the original) for being a though bastard to kill with the minigun
![Mad :x](./images/smilies/icon_mad.gif)
![Cool 8)](./images/smilies/icon_cool.gif)
+ some oldies that I can't remember right now.
Oh, just remembered, the final boss from The Chaos Engine was extra neat.
You know this game, man I loved that game...got to go find it now, I should still have in tucked away in some dark corner...