I'm not sure if my list will stay like this, but at the time.
#1: Pink Floyd(The only one I consider concrete)
#2: The Who
#3: Rush
#4: The Beatles
#5: Not a band, and my #5 is the most subject to change, but right now, it is Devin Townsend.
1. Emperor
2. Empyrium
3. Dissection
4. Arcturus
5. Behemoth (Saw them recently. They put on such a great fucking performance. \m/ Polish Metal \m/)
6. Immortal
7. Borknagar
8. Nile
9. Naglfar
10. The Berzerker (Pure fucking aggression