I've always loved Live at Leeds, but the expanded "deluxe version" is truly killer. It has 33 songs, with the second disc being the full version of Tommy live. I just listened to the first disc (12 songs) straight through the other day with PS-1s and I had such a great time. The Pete and Keith banter and the energy captured are awesome. The Tommy set is also great to hear live as others have said. I have the Isle of Wight DVD but I should really get the CD because it is not edited down. Should be a fun comparison with the full Leeds.
All that said, however, I think that The Who's best albums are Who's Next and Quadrophenia, and like Coltrane I change my mind which one is tops depending on mood, etc.