It depends on many factors. I have heard certain LIVE albums that truly capture the 'essence' of the time. Although the recording is sometimes poor and doesn't translate that well. Hendrix at Woodstock or Band of Gypsies are prime examples of really great 'in the moment' type of recordings. Some of the MTV Unplugged appearances worked well, but they were recording well and inside a more controlled setting than outdoors or in a noisy concert hall. I like the live KEEP ON ROCKIN' IN THE FREE WORLD that Neil Young did with Pearl Jam far better than the studio cut.

It also depends on if the band is a band that is used to playing live or if their sound is mainly studio processed. Dream Theater sounds very similar live as they do in the studio, while other bands just don't sound very good live no matter how good they are in the studio.

I can't think of too many LIVE recordings that I frequently visit though. Maybe the Pink Floyd PULSE. Roger Water's in Berlin is also quite good too. Queen in Webley. I am sure others are out there, but nothing that I just love to death necessarily.