Man, some of you guys are making me feel like an entry level prog nerd here.
Pink Floyd opened the flood gates for me, so they will always have a special place in my heart. Recently, I've been geeking out over those "Immersion" box sets that come with some previously unreleased remastered live stuff from the early-to-mid 70s, including a full performance of DSotM, as well as some live Animals material (back when Dogs / Sheep were Raving and Drooling / You've Got To Be Crazy, respectively).
Its great to hear the whole gang playing together, at their creative peak. Its one of the reasons I've always preferred that Pompeii live DVD over something like PULSE. And while I love PULSE a lot, everything sounds a bit too polished, and they can't quite wash away that thick 80s veneer.
Something about Gilmour's guitar... I dunno, its got this raw bluesy energy that you just can't find in the post-split stuff. And hey, Waters vocals! The guy could carry a tune back in the day.