Ace Frehley is underrated as a guitarist. His licks are tasty and fit well within Kiss songs. He won't dazzle anyone with unusual skills or proficiency, but his solos are usually tight, somewhat intricate and, many times, melodic within the context of the song. Given Kiss's popularity, I'm surprised more rock guitarists don't acknowledge him as an influence. Also, Elliot Easton of the Cars is very underrated. He says a lot in a solo in a short amount of time. If the Cars were a band that was more guitar-oriented or driven, he would've had a better showcase for his talents.