Hard for me not to say Duane's Allman Brothers with Skynyrd a close second with a distant third being GnR
Tool or Zeppelin. It's hard for me to narrow it down to just one. I love Marshall Tucker, the Band and Nitty Gritty Dirt Band too.
Great list. Everyone of those bands has a song I love. Tool used to get me amped up beyond belief before a big game.