Look, huge Lifeson fan, here, and have often thought him to be the unsung hero of that band; for all the greatness that is Lee and Peart, other than the drum part of Tom Sawyer, the memorable riffs by and large are Alex's.
Having said that, he's not often mentioned in the same breath as the Page's, Blackmore's, Clapton's, and Hendrix's of the world. He's just not. I'm not saying that's right, or just, or fair, but just is. I think in part that's because he's not a flamboyant rock star like some of the others, but also because, what's his signature song? He has great solos, great riffs, great parts, but FOR THE NON-RUSH FAN, where's his "Wonderful Tonight"? "Layla"? "Smoke..."? "Stairway..."? "Little Wing"?