Aside from being the world's best sidekick, Watson is definitely the president of the Sherlock Holmes fan club. Watson admires Holmes so much that he basically devotes his entire life to Holmes. In fact, Watson almost doesn't exist outside of Holmes. But not all types of admiration are taken to such extremes in these stories. Holmes is universally admired, and we see signs of hero-worship in Stanley Hopkins, Inspector Martin of the "Dancing Men" case, and even Inspector Lestrade on occasion. Holmes himself rarely admires anyone, except for a small number of clever nemeses. People often seem to bore Holmes. Neither Watson nor Holmes can see past Holmes's awesomeness at times, but Watson's admiration isn't totally blind. He definitely expresses annoyance with Holmes on occasion. Admiration can be a positive emotion, but it's often a source of blindness in these stories.
Watson admires Holmes so much that he's nearly blind to his faults, and the faults he does recognize get turned into virtues.
Watson admires Holmes professionally, but he often expresses aggravation towards him on a personal level.