i'm a blues guitarist myself and i've immersed myself in all sorts of guitar music. i'm pretty familiar with most of the great players but when it comes to my personal favourite i always come back to Peter Green. weird i know and i'm sure that's a pretty rare choice but his guitar (and vocals) seem to get to me. i think that's what the blues is really all about too.

Struggled with a drug addiction for a while back and 'jumping at shadows' still gets to me when i listen to it now.

By the way, I'm talking about Peter Green from the original Fleetwood Mac era. Had the chance to meet him recently and hear him play with the Splinter Group. The magic's still in there somewhere but it doesn't come out much.

I don't know if he would be considered the greatest, but i would have to say my favorite at the moment would be Buddy Guy. I heard him for the first time when i was watching Eric Clapton's Crossroads dvd and when he came on i was just blown away by how good he was. Plus the guitar he used was amazing and i wanted it so badly. But I just started listening to some T-bone Walker recently and he really does some amazing things. I haven't gotten any of his records yet though because of all this snow where i live.

Probably not the greatest, but one of my favorite has to be Robert Johnson.

Huh? Says who? At worst, he is a top 3 or 5. Clapton built his entire career on him, and is still milking Johnson for all he can.

I said probably not the best because I think in the overall scheme of blues, he isn't the best. In the early detla scene, he was the best out there, but as the blues scene moved into chicago and texas blues, other guitarist emerged.

You can't make comparisons so easily between the Delta and Chicago (I'm not even going to consider "Texas blues"). By way of what transpired in Blues, and indeed music history, most people would be more impressed with Albert King's work than Johnson's. Not I, though. The Delta has always been more intriguing for me. Gimme Lead Belly over SRV anyday (for musically quality and guitar virtuosity). When I first got into the Blues (a while ago; actually, was my first preferred style of music; first CD I ever bought with my own money was BB's How Blue Can You Get) I gave all the standard artists a listen. All of the Delta Bluesmen got my attention right away. When I started listening to Chicago, and then 'blues-rock', I was mostly disgusted (for lack of a better term) than intrigued. Very few Chicago Bluesmen - with exceptions of the harp players - impress me. Blues rock to this day I find a very pale, not-nearly-up-to-par version of Delta, but with many great shining moments. Once Muddy plugged in, so many followed suite. And it's unfortunate, because Muddy's early career - going as far back as the early 40's - was great. That was when he played Delta. Just the same, I understand that evolution needed to flower, and if the Blues didn't move north, it would have died, right around the time when Skip James went missing.
These days, it's great to have so many great talents playing in a Delta style. If I may offer my favourite, and the cat who I think is carrying the Blues and needs much more recognition, Alvin Youngblood Hart. Pick up his debut, Big Mama's Door. Stellar.
As for Johnson:

I like to believe that this is Johnson, bald, and without his hat.

Texas blue is my favorite, so naturally a texas guitar player is my favorite. (not talking about robert johnson). I just like the sound of it all and the rythem of it all. Delta is cool and I can't stand chicago. Everything is better in Texas

Its hard to name the greatest, I tend to like John Lee Hooker the most of all the classic blues guitarists (if judging on guitar only), also that dude in my avatar is pretty good...