I just started collecting this year after setting up my first home theater. Here's the concerts I have and like. Obviously it's gonna depend as much on your taste in music and bands, but the shows in the "best" group are all excellent. I have a couple of DVDs that the shows or the recording just are too poor to even recommend
Best:
Concert for George (this is an unbelievable concert)
Allison Krauss & Union Station Live
Peter Gabriel - Growing Up Live
Cowboy Junkies - Open Road (this is only Stereo/Pro-logic)
Neil Young at Red Rocks
Metallica S&M
above are sort of in order preference - but all great
Also good:
Steve Hackett: Somewhere in South America
King Crimson - Eyes Wide Open
Procol Harem Live
Best:
Concert for George (this is an unbelievable concert)
Allison Krauss & Union Station Live
Peter Gabriel - Growing Up Live
Cowboy Junkies - Open Road (this is only Stereo/Pro-logic)
Neil Young at Red Rocks
Metallica S&M
above are sort of in order preference - but all great
Also good:
Steve Hackett: Somewhere in South America
King Crimson - Eyes Wide Open
Procol Harem Live