TV on the Radio is one of these bands. They played SLC last night to support their second LP, "Return to Cookie Mountain" (which appeared at the top of several best-of-2006 lists). It's a challenging and almost overwhelming album of so many textures and layers, you can't help but listen to it time and time again.
The opening band was Subtle, but we missed their entire set because we were waiting in line at the bar. We got back near the stage just before TVOTR came out, blaring their avant-garde tunes. The band was very animated and kept the crowd jazzed for the entire show. Unfortunately, the entire show only lasted about 90 minutes. Regardless, these guys will one day be legends, and it was great to get to see them live.