For shred / virtuoso:
: Surfing With The Alien, Crushing Day, Always With Me/Always With You, Ten Words (although those last two are less flashy, and instead beautiful pieces of music).
: Lotus Feet, Whispering a Prayer
: Revelation Mother Earth, Crazy Train, Goodbye To Romance
: November Rain
: Viking Kong
: Far Beyond the Sun
: Comfortably Numb, Fletcher Memorial Home, High Hopes, Great Day For Freedom
: almost anything, he was really in a world of his own. Machine Gun, Woodstock Improvisation, Fire (Woodstock 69), Little Wing are amazing
: Bad Penny, Philby, Tatoo'd Lady, Shadow Play.
And also Brian Setzer on Rock This Town, just unbelievable technique
And if I had to pick between all those, I'm still torn between two: The raw, beat-up guitar, and adrenaline-packed performance of Rory Gallagher http://www.youtube.com/watch?v=GHzOJKn7vnc
and the technical brilliance and soaring beauty of Steve Vai's amazing tribute to Ireland: http://www.youtube.com/watch?v=8KUSkGeaUPU
Both absolute masters of the guitar, but in completely different ways