I've seen a fair number of concerts in my day, but Floyd in '94 (twice) was at or near the top...not because the band was so incredible, but because the songs and the show that went with them were. Watching the band is almost incidental at a Floyd show.
That of course was without Waters, as the band had broken up in the early '80s because, well, because Roger is a godawful pain, that's why. Here's hoping he's mellowed and I can pay much more than I should for a ticket to see 'em all together.
Here's "One of These Days" from the '94 tour. You'll have to trust me, video doesn't do justice at all to the sheer ominousness of the light show and atmosphere.