There's a huge difference between being technically difficult and well, soulfully difficult. When I started playing 7 or 8 years ago, I was so impressed by anything extremely technical. But as you progress and mature, you start to realize that there's alot more to it than that. Along these lines, I consider Satriani to be a HORRIBLE musician, at least as far as Surfing with the Alien is concerned. Take away the guitar solos in the songs, and what do you have? NOTHING. A mediocre garage band song at best. His songs were merely a train for him to solo over. Although I haven't listened to his later stuff, I'm sure that he's progressed past this flashy stage, realizing that it's only skin deep.
So that being said, the solo that draws the most emotion from me, and I could never even attempt to duplicate, would have to be the David Gilmore solo in "Echoes, Part 1" off of the Live at Pompeii video. Not technically hard, but the soundscape he creates is simply amazing.