Best Live Album Ever...

How the West was Won. Amazing Led Zeppelin from their peak

I second the choice of Hot August Night by Neil Diamond -
electric performance with superb dynamics. Neil sounded so energetic like he could go on forever. After this, he later mellowed and his songs became too saccharine for my taste. Why and how did he change so much? That's quite a mystery. Any thoughts, anyone?

I still come back to this thread for the great suggestions.  
Here are two more very fine albums:

Dan Fogelberg Live at Carnegie Hall
Harry Chapin Greatest Stories Live

Some that are not mentioned above,
King Crimson Absent loversThe Who live at Isle of WightELP welcome back my friendsMothers Roxy and elsewhere
G

Lou Reed-"Rock n Roll Animal"