Bolded ones are really good (note, most of these I only like one song they did, but this isn't the case with Boston or Rare Earth).
Boston
Chicago
Cream
Strawberry Alarm Clock
Sugarloaf
Rare Earth
Blood, Sweat and Tears
Thin Lizzy
Van Halen
ZZtop
Iron Maiden
The Doors
Jimi Hendrix
Steppenwolf
Kansas
Deep Purple
The Beatles
Iron Butterfly
A Flock of Seagulls
Creedence Clearwater Revival
Dire Straits
Santana
I'll try and think of more...