Beatles - poor sound systems, can't hear over screaming women. They stopped doing live shows because of this. The Who and the Dead beefed up sound reinforcement practices to stadium tour.
Elivis - similar to above in the early years. Later years, maybe worth it...68 Comeback era before Vegas would be better.
Floyd - Late 70s Floyd for sure would be great. Getting the best of their strongest albums with their live production and light show on point.
Zep - I don't know how this wouldn't be the winner if we're talking mid-70s. Crushing power, every song is a spectacle. Only thing is there are plenty of shows on film, so maybe not as rare to see as a full prime Floyd set.
