John Mayer has the most impressive range of guitar faces I've ever seen. Ok, so maybe he looks like he might cum all over his guitar at any moment but his facial expressions are amazing. There's the pure ecstasy face, the "I'm pissed but still enjoying this" face, the "it's so good it hurts" face, and many more.
Just imagine...this is what Jessica Simspon saw every night she was with him! Which brings me to the question: "Can you fake guitar face?"