I think everyone knows by now that mine is Mark Knopfler. I'm not saying he is the best ever, but he's definately up there. He has a very unique style. He's an old fashioned finger picker like a lot of the blues and classical musicians of the early-mid 20th century. Most rock guitarists tend to use a pick, but his unique style seems to give him his own sound. I love a lot of his complex guitar licks, solos and other compositions. He blows me away with not only the things he plays, but also the stuff he writes. I love his live material either with Dire Straits or as a solo artist because you can gurantee that he will extend the songs wherever he can and add solos and other bits and pieces. He's a genius and to see him play live was great. I just wish I could have been closer to him so I didn't have to watch his fingers through binoculars.
As for other players that I admire then see my signature pic, and add to that list Bryan May, Paul Kossof, Joe Perry, BB King, etc, etc. There are as I'm sure many more that are great but I haven't had the chance to experience or discover them yet. I believe Joe Satriani and Steve Vai are worth a listen but I don't really know where to start. If anyone would care to suggest any more....?