Tool and Zeppelin are my favorites, although I will always put Zep at 1.

1. Tool
2. Neil Young (and Crazy Horse if that helps him qualify)
3. Rage Against the Machine
4. A Perfect Circle
5. Beck (and his band, lol)
6. Simon and Garfunkel
7. Crosby Still Nash and Young
8. Nine Inch Nails
9. Jane's Addiction
10. Fleetwood Mac

REM, The Doors, Hendrix, The Beach Boys, Stone Temple Pilots... When I read the "American Bands" request, I thought I would struggle name 5... turns out there are a lot more than I realized. Aerosmith, Van Halen... could easily be in the top 10. The Beastie Boys and Weezer on any certain day, lol. And if we did an all inclusive list then the American bands would still keep about 5 in the top 10.