A large number of Iron Maiden songs or Joe Satriani songs.
Both of them artists/groups are simply breathtaking when it comes to a hardcore solo on a guitar.
If i had to truely pick any one song out of these two, sadly I'd leave my Iron Maiden and pick "Surfing With the Alien" of Satriani or possibly "Summer Song".
Hell.. thats not fair.. maidens "Aces High", "Dont Look to the eyes of a stranger" solo at the 5 min 20 sec mark (sry I love this song
), or even "The Educated Fool" around the 3:30 mark, or....
Theres always the allmighty "Thunderstruck" by the one and only ACDC. Best damn blood flowing song ever made for mankind.