Kamelot. I enjoy every song they've made and would never get bored of listening to any of them. Seriously you could just keep playing Center of the universe or Wings of despair forever and I'd be happy with that.

Define "listen to for all eternity".
Like, "plays all the goddamned time to the point where you don't even here the music anymore"-eternity, or "this is the only band you can listen to, but whenever you want it"-eternity.

Anyway... I guess right now, it'd have to be Stevie Ray Vaughan and Double Trouble.
Sweet music. What else can I say?

Only band and you have to listen.... it's hell.

Pink Floyd or Tom Waits, both have lengthy and large discographies and both have very eclectic and varied sounds throughout their careers

John Coltrane

QFT!

However, if I had to choose, I'd be stuck between Newsboys and VNV Nation.

You know, listening to Pink Floyd for all eternity would be a very evil, wicked punishment deserving of Hell. It really would be.

Meanwhile, I'm caught up on a choice between Mozart and Beethoven. I don't know which would have the longest lasting intellectual stimulation. Mozart has the bigger catalouge, but Beethoven has written the most amazing pieces of music ever.

Oh, was this supposed to be modern music? Fuck that shit, I'll listen to the screams of agony.

the barenaked ladies, because then it would be like Canadian hell, and likely just like, really bland and cold with not many people around.

and hey, there'd be poutine!

No one said Queen yet? They have a really lengthy discography and all but a very few number of songs are gold. And the ones that AREN'T gold, are still better than almost anything else that gets shoveled out today. (I'm looking at YOU Beyonce, specifically that new horrible song talking about how she is single.)