Man, that's a tough one. There are lots of really good ones out there. But it seems like bands have really upped their game on live albums as time has gone on. Hard to say how much of that is attributable to tighter performances, much more substantial backing tracks, or post-production wizardry (including substituting studio performances with "live" performances). But there have been lots of really good ones. I won't get into video, because that is an entirely different animal. But just in terms of CD live albums (that are not DT), here are some of my favorites:
From back in the '80s and early '90s:
-The aforementioned Operation: Livecrime -- Man, SUCH a great live album. This one had it all. I have no idea how much this release may have been doctored after the fact. But even if it was, those of us lucky enough to have seen the band on this tour know that they brought it, and that the final product we got on this release was very much consistent with the band's live shows.
-Y&T, Yesterday & Today Live -- From Y&T's last performance on their "farewell tour" before they reunited several years later. Terrific song selection. Terrific performance. This is probably one of my desert island disks.
-Scorpions, World Wide Live -- I don't care that this is cobbled together from multiple shows or that it had extensive post-production doctoring. It is awesome.
-Dokken, Beast from the East -- Classic.
-Pink Floyd, Delicate Sound of Thunder -- This and Pulse are both fantastic.
Modern:
-Epica, Retrospect -- I would rather listen to this than their studio albums. And I regularly do just that.
-Within Temptation, Black Sympony -- The only problem with this performance is that the guitars are a bit low in the mix and get buried by the orchestra, so even the heavier songs don't sound as heavy. But still a fantastic album.
-Nightwish, End of an Era -- Such an amazing performance. If you like the Tarja era of the band, it doesn't get any better, despite Tarja and Marco being sick.
-Neal Morse, Morsefest 2014 -- He has so many great live albums, but I went with this one both because of the set list and the performance.
-Transatlantic, Live in London -- Well, the Whirlwind is my favorite album from them, so...
-Def Leppard, Viva Hysteria -- Mirrorball was surprisingly fantastic as well, but Viva Hysteria is exactly what fans of Def Leppard could want in a live album.
-Stryper, 7 Weeks -- When I think about seeing the band live, I listen to this disk and think, "why bother? It won't be any better than this."
I could list many more, but that is a good start.