This thread has provoked a wicked game of hide-and-seek with my now unreliable memory. I humbly ask to be excused if I repeat stuff I've already mentioned on this site.
As much as I love my Zeppelin albums, I enjoyed their live concert still more. The same goes for my encounter with Bob Marley and the Wailers, who I saw at the Roxy. I saw the Byrds several times, and to my ears they were never nearly as good live as they were in the studio. It was the exact opposite with Crosby Stills Nash & Young. The concert I saw with Herbert von Karajan and the Berlin Phil tramped all over the recordings I have that feature them. My experiences regarding Pink Floyd are 50-50. Likewise, both live and canned Chuck Berry was equally excellent.
I could go on. And on. And on.