In response to devildavid's comment:
Live performance could be a criteria, but I don't put much value on special effects such as light shows, lasers, props, etc.. I put more value on how a band sounds live. But I haven't seen a lot of bands live so it would be hard for me to judge based on that.
Again, fair enough. For myself, it's a critical point.
Agreed it's primarily about the music/quality of performance, but there are such things as showmanship, band interaction and improvisational skills that contribute to the overall live experience.
After all, concerts are inherently multi-media events. Even the smallest venues have their lights and smoke machines and mirror balls.
And as far as effects go, I think there are innate differences as well between, say the pyrotechnics and camp theatrics of Kiss vs. the psychedelics of The Dead, or even the audience-band interaction of a Phish show.
FWIW, Led Zep never did much of a light show spectacle; their legendary live shows often stretched 3-4 hours, featured a lot of improvisation, medleys, curve balls and virtuoso-like solos.
Granted, not every show is perfect, but that's also the point. Within each show there are always moments of genuine brilliance, some longer than others, but all of them shared by the band and audience alike, whether the crowd is 1,000, 10,000, or 50,000.