I agree, everyone has their favorites at different types of music. Texas Blues , Stevie Ray did it for me. Then how do you compare Stevie Ray with Chet Atkins or Jerry Reed or Merle Travis , Doc Watson. Everyone has favorites and does that make them the best , no but each have a unique style that made them a treasure to watch and listen to.
After seeing Eric Clapton at the Crossroads festival and just about every Great Guitar player was there for a 3-day Guitar Lovers Dream. I don't think Clapton was the best by a long shot but his "Tone" I thought was the best and he really plays with feeling.
I watched many of the players jam during the 3-days and Jimmie Vaughn played in nearly every jam , one that was especially cool was with Eric Clapton, Buddy Guy, BB King, John Mayer all great players , but the guy I thought was best jam musician and ready without a cue at all times to pick it up and keep things tight was Jimmie Vaughn and I don't think he would make anyones top list of guitar players but just a wonderful musician.
Then move on to Bluegrass, and how do you compare Tony Rice, Clarence White, or many of the great Flatpickers with others.
I say enjoy them all and be thankful they have given us such a great variety to enjoy