It's been a long time since I've heard it so I'm not sure if it's an actual "solo", but Neil Young's guitar in his "Like a Hurricane" makes it one of the great rock-and-roll songs of all time. H
Another underrated guitarist is Kim Simmonds of Savoy Brown. Some of my favorites are his solos in Raw Sienna.
I would go with Joe Walsh - Hotel California. Here's what Guitar Magazines readers thought. Glad to see ETer's like to rock. http://guitar.about.com/library/bl100greatest.htm
I used to frequent a bar on the Northside of Chicago called Kingston Mines. I saw so many great Blues guitarists there week after week. Buddy guy comes to mind as one of the great ones. BB King can also play a few licks.
What do all you guitar pros think of Santana's solo on "Why Don't You and I" - the song with Chad Kroeger of Nickelback on vocals? Man, I keep rewinding the solo over and over again.....gives me chills.
I think Santana is great for many who don't go beyond pop culture in their music collection. I like the guy, he's got his own recognizable tone, but for chills the same ole blues lick doesn't do the trick for me anymore. Especially when you hear it in every single solo, lol. I'd rather listen to Satch or Robben Ford, who can give me a melody i can hum as well as keep me wondering what amazing lick is around the next bar.