Not necessarily the best or your favorite, but the most important, and influential. It'd be pretty hard not to argue Radiohead, and in fact they have been regarded as "the most important rock band in the world" since 1997 when OK Computer came out.
What's your thought?

I think judging by your username...you are a bit biased...just a bit...

Radiohead is incredible, no doubt. Classically trained and extremely talented. (Hello... Spinning Plates live? Last Flowers? Makes life worth living.)

BUT... I would have to say Nine Inch Nails, myself. For sooooo many reasons.

EDIT: In existence, that is. It would be hard to top the Beatles on the All Time list.

I think Alice in Chains was big for Grunge, but I can't think of a band that did more for their type of music than Metallica did.

Edit: I agree with Vendetta, the Beatles were huge and extremely influential to rock as we know it. And I know there will be those who mention Zeppelin, but I just can't stand their music. Plant's voice is like fingernails running down a chalkboard.

Just a teeny tiny bit. I think Arcade Fire is quite influential, though. Even Coldplay's ripped them off a bit.

Oh, and I mean the most influential band in the world RIGHT NOW. The Beatles, obviously, win for all time. But what about right now?

@Kid_A: This topic is still a little vague. I mean, some people might think, say, Black Eyed Peas is the most influencial/important band right now. I also don't think you can single out a band as the best in the world. What do you guys think?

Sgt. Pepper's Lonely Hearts Club Band
Right now? I think the music right now sucks. I listen to stuff from mainly from the 60s - 70s and a little 80s.
Most important in the world right now? I guess Metallica.

I think you'd have to define some parameters. Like JohnnyB said, a question like this will yield answers all across the spectrum. Are we talking hard rock, hip hop, wizard rock, skweee, death metal, what?

@Jerichoholic Josh: Music right now doesn't suck, you're just not looking in the right places. There's a metric ****ton of great music being made, it just doesn't make the radio most of the time.

Where should I look?

The rubber band. Without it, newspapers would be so hard to keep together.

Depends. What kind of music do you like? You listed three decades worth of stuff. Any bands or styles in particular?

@Panda: Never heard of Skweee before, but I just checked it out on Wikipedia and youtube... Pretty cool stuff

Elvis, The Beatles, Elton John(<- Love these two ->), Billy Joel, Bob Dylan, Tom Petty and the Heartbreakers. Thats the people i have waiting in my passenger seat when I get off work.

Yeah, I just found out about it like three weeks ago. It's pretty fun stuff. Check out Daniel Savio if you like it, he seems to be a forerunner in this type of music.

EDIT: Oh, and I know it's not skweee, but I can't help but pimp The Mae Shi. HLLLYH was my favorite record of last year, hands down.

@Jerichoholic: Ah, classic rock fan, eh? I understand why you say music nowadays sucks! Anyway, I say check out Little Steven's Underground Garage. It's a lot of garage rock, but he's definitely a fan of the eras you dig and I think you'll find some gems in his show.

I think everyone should listen to Little Steven's, actually, it's really great radio.

I shall when I get home

Coldplay has fans?

The Beatles easily. Most of the bands listed were influenced by them.

Kid_A, you're on point with Radiohead, but Arcade Fire? ARCADE FIRE? C'mon, what have they got, like 3 decent songs? I can't imagine people 10 or even maybe 5 years from now saying, "yeah, those Arcade Fire guys really tore it up!" They'll end up in the same place as Modest Mouse, and hopefully the downward-spiralling, increasingly disappointing Coldplay.