I'd say Jack Frost rates as really obscure.
Texas Twister is a good one, I think he has been seen in the last 10 years though.
Torpedo from Rom for sure, he was killed by a Dire Wraith though. I think another hero later wore the suit and was called Turbo or something, they'd rate as well.
Arabian Knight from Contest of Champions doesn't seem to get much play unless I've missed something.