Controversial opinion time:
Even though "If You Want Blood, You've Got It" is one of the all-time monumental live albums, Bon Scott giving some of the greatest vocal performances of his life time on it, there's not enough that distinguishes it from the studio versions for me to really love it. There are two tracks though that completely eclipse the originals ("The Jack" and "Whole Lotta Rosie") but unless I wanted the closest thing to Bon Scott porn, i'd rather listen to the studio versions. Don't like the grimy 'plug in and play' punk vibe to the guitar tone on it either.
N0w on to my picks:
The Who - Live At Leeds:
Even though the Tommy said is quite the mixed bag and generally fails to match up to the original album, the remainder of Live At Leeds is utterly flawless. Entwhistle's bass is so prominent and electrifying, and the ferocity of the playing is overall much louder and closer to Zeppelin territory. Sure some of the songs offer little new to the studio versions but aside from some of the Tommy tracks as mentioned, the arrangements are so much grungier that I would rather listen to them overall. I still like the studio versions of "My Generation" and "Magic Bus" for what they are but damn is this one of the most exciting things in classic rock's history. Turn it up loud!
Judas Priest - Unleashed in the East:
With a savagely dry guitar tone and a ramped up energy that obliterates most of the original renditions of these songs, the cliche that the band and the audience feed off of each other could not be more better applied to this very album. Again, "Victim of Changes" is fairly redundant, and I like the studio versions of a few of these tracks about equally or just slightly more, but as an experience, the album is worth owning by any metal fan. If you can only have one classic Judas Priest album, get this.
Motorhead - No Sleep 'Til Hammersmith:
I've just began to get really into Motorhead beyond their main hits and this alongside Ace of Spades is the perfect starter pack to at least their early sound. The tracks from Overkill pale in comparison to the monstrous arrangement of those same songs here but even on weaker entries, the feel of the album just kicks your arse into oblivion. About as metal as one can get without losing their tooth.