Argorak

Try the last boss of Ikaruga, a GC space-shooter. Here's a brief description. The thing lays down a moving grid of bullets while blasting away at you. And all the while, you can't fire a single shot back...

Well, I know these have almost certainly been mentioned before, but any boss past the 3rd boss of Ikaruga. Phalanx on "funny" mode was just...evil. "Do I leave this fleet alone and have to dodge 50 bullets, or destroy them and still have to dodge 50?" The S.O.R.N. on Wizardry V was pretty hard too. Blasted out massive spells at you, AND was resistant to spells himself. Then again, the data got wiped after I got to him... Also, try Bagan in Super Godzilla...without turning into Super Godzilla. Edit: Sologamer, I'm not very good at MK either, it was just something I found out by accident. Oh, and on SSBM try out the Insane(?) Melee . The one with the wireframes that smack you around like a rag doll. Can only take out 6 or 7 at most (I forget which). The event battle with Ganondorf, Mewtwo, and Gigabowser is pretty hard too.

Man, I hate Shao Kahn in MK Trilogy. My cousin and I just can't beat him (might have something to do with the fact that I suck at MK). It's not too hard to beat him with Sub-Zero. Just use his ice shot, and Kahn does his knee move -- and ends up in upper-cut range at no danger to you. Do an uppercut, then repeat. If you do it fast enough, you may even catch him as he gets up! (Or did you have to use a roundhouse???)