15. Allman Brothers Band, 'Live at Fillmore'
This double-LP classic of jammed-out blues and rock is, like any good trip, guided by a spirit of adventure and full of surprises. Many of the best parts come courtesy of the guitar tandem of Duane Allman and Dickey Betts, who are either locked in liquid harmony or taking off on jazzy flights of fancy. When they get seriously cooking on "Whipping Post" and "In Memory of Elizabeth Reed," all you can do is shake your head and say, "Siiiiiiiiiick."