Kiss, ACDC, Black Sabbath, Dio, Whitesnake, Bon Jovi, Motorhead or Guns N Roses  

Guns N' Roses.
They are legends.
I never, ever get tired of their music. I feel like it has so many back stories and different meanings. I absolutely adore it. And they have some of the purest rock epics ever written. You don't get epic songs like that now.

I love the other bands too though!

boy....throw in Iron Maiden, Judas Priest, and maybe some Ted Nugent, and you would have the soundtrack of my life.
but out of the list you give, i'd also have to go with Kiss just because their "Alive 1" album was the music that introduced me to "Head Banging, Ear Splitting, Air Guitaring, Heavy Duty Rock-n-Roll!!!
a close second would have to be Black Sabbath...of course i can stick Dio and Ozzy in with that one.(yes, and Ian Gillian from Deep Purple)
and one more personal opinion...Guns N Roses would still be one of the greatest rock bands right now if Axl Rose didn't turn out to be such a PUNK! (where's "Chinese Democracy now Mr. Rose? the "new" album you've been releasing for the last 12 years???)
anyways, Rock On F.C.1990

Hard to say they are all great, but Kiss and Whitesnake are at the top I think.