I am sure every world class guitarists knows who Mark is, they would have all heard and loved Sultans of Swing, and in the 80's Mark was everywhere and Dire Straits were huge. I am not into shred music at all, mostly because there is no emotion and feeling in it, but there are a few tracks I like from Joe Satriani:
Tears in the Rain - An acoustic/classical guitar piece.
Always With Me, Always With You - Good guitar sound and good melody
Flying In A Blue Dream - As above
But even with the last two above he can't resist going a bit mad in the middle of it!!!
Saying all that Mike Oldfield is in my opinion the greatest composer and player of instrumental music.