Tomorrow's Child. To me they're probably the best band that never even got a shot at it. They were picked up by Arista Records in 1989, and then got screwed over by the label. Their albums got released long after they split up. The S/T debut is awesome. The second album Rocky Coast, Rough Sea was a bit more polished. I believe this one was made up of the Arista sessions.
They also had a song on the Street Survivors compilation. (featuring LA's best unsigned bands) Another cool band "Fire" (featuring Mike Guy of House of lords fame) also had a song on it. They should have been huge as well.
Tomorrow's Child were from Los Angeles, but didn't sound like Crue or Ratt. The guitarplayer Rik Schaffer is great. Very smooth sound, almost a bit similar to Mark Knopfler.

/Daniel