You know who I really miss?
Amok.
He showed up in the early early 00's, maybe even super-late 90's. He was just a dude with a suit of power armor and he could combine his hand blasts into an attack that could throw Clark to the moon.....but wasn't powerful enough to actually hurt him. He had fought Superman a few times and wasnt enough of a villain for Clark to remember, and that always pissed Amok off.
I always thought there was potential there; sort of Superman's very own Kite-Man in a way.
Oh, and Ignition was a fantastic villain who never got his due, either. Wish they had done more with him, he had a really interesting story.