There simply isn't a "best". It has no meaning as most listening is subjective.
Best at what? Speed and accuracy? Composing, feel, or the ability to copy another guitar player's licks?
Yngwie Malmsteen is an incredible player. I remember being one of the first if not the first in my area to own his solo release. I got hooked on him when he played for Alcatraz. I can honestly only listen to him for short periods. I find him technical and overall excellent but the style is boring and repetitive IMO. Not everything he does, but the neo-classical stuff seems to leave "emotion and feel" (subjective) out of it for my taste. He's awesome though and I like him if that makes sense, just not for long listening sessions.
Jimmy Page is a player I adore. He is often sloppy, but that makes his style unique and to a certain extent, Ed Van Halen could be sloppy, although he was usually under the influence and it was often during live performances. In the studio he was sharp.
Jimmy Page wrote excellent music as did Ed. Ed is also a sensational rhythm player.
If you were to define best, the criteria would probably have to be based on the technical aspects of playing. Classical guitar has a very "schooled" approach. The blues,,, not so much. But can the true classical musician go play the blues and blow you away? Maybe some, and vice versa for the blues player.
There's probably an unknown out there that can play every style to a T and we'll never know who they are.
I can't and won't pick a best. Somebody mentioned earlier that "favorite" and best are completely different and I agree. My favorites change frequently as does my mood and that's the beauty of music.
All of the above is just my opinion. I love guitar and some of the artists mentioned here, I've semi forgotten about or have never heard. Now that I have a dig them.
Here's a solo that I've always enjoyed. Neil is not the center of the band, Pat is but he's the music mastermind. He's rarely mentioned as a "Top Guitar Player" but listen to this slick little solo that totally fits the song.
One thing I like a lot about really good and humble guitar players is that they always find something good to say about another player.
My silly rant is over. I love music of all kinds and players as well.
EDIT:
Thankfully there is an edit option here. That rant was filled with misspelled words, some were auto corrected to words I didn't want to use at all.
I'm not offended if anybody thinks I'm an illiterate moron. I have it coming after what was first posted LOL!