I want to see bands engaged by their own material and not too concerned with the people watching them. Now, that in itself can be "putting on a show" for those on tour, because people in a strange town with an upside down sleeping schedule playing the same set of songs every night for a month (or two!) could probably be very bored while playing... so bothering to look interested is probably an effort in itself!
"Putting on a show" in the standard sense just turns me off. It just seems so contrived, and if I want to be "entertained" I'll stay the hell home and read a comic book. And for all the extended singalongs, drum solos, and other miscellaneous shit that happens at shows, the band could have played another song (or two!), which is what I thought the people were coming to see...
But don't mind me, I make frowny faces when the smoke machine is firing off. After going to a couple punk shows here in town where they don't do ANYTHING, not even darken the room, for the performance... that's what I want to see. The band. Playing. But a metal band shows up, turn out the lights and cloud of the room! Fuckers.
As for doom shows... Reverend Bizarre was just intense, aside from when they brought everyone out shirtless for Doom Over the World. Fucked that song all up, that did. Ablaze in Hatred was awesome too, playing to an empty room but the little details of the music just had me entranced. That kicked ass. Yet (as I've mentioned today) Swallow the Sun gave a no-frills performance (well, lights and smoke...) and they bored the hell out of me.
I like the Ozric Tentacles/Flower Kings kind of vibe, just play, talk to people a bit, and play some more. Watching a non-metal band give an instrumental workout makes it obvious how silly the heavy metal frowny faces (and the guitar players making out with the invisible ghost while soloing) can be. When I saw the Flower Kings do Garden of Dreams live, just saying the name of the song made the people in attendance ecstatic, no bullshit needed. Although it was hilarious when they were on the home stretch, fucked up, and I forget who it was that said "woops, we have to start over." Cool save there, the whole place had a laugh, and they finished up the song without anyone thinking less of them. (for all I know they did that same bit every night and it was just part of the show, haha). Opeth concerts, at least as of a few years back, have this unpretentious, "We're here to play music and you're here to listen to it" vibe and I enjoy that best. Cynic was like this too as I recall.
More adrenaline-fueled bands are in a no-win situation, I think. Playing in this kind of unpretentious manner that I like on stage will emasculate the material being played, yet all these death metal bands staying "in character" during the crowd banter makes them look like frickin' fools and often reveals how comically absurd their music is in the first place.
Or they could go all Anal Cunt and attack their fans during the performance. Wondering when it's going to be your turn to run away from Mr. Putnam distracts from certain lacking characteristics of their music.