That's a tough one. Like a lot of the guys here, I got started when Guitar Player Magazine was giving away plastic flexible albums with their magazine. Songs like Yngwie's "Black Star", Cacophany's "Go Off", and Satriani, got me introduced to the genre. At the time, (for me), it was anything that could be cranked up loud and sound impressive to my friends. I worked backwards and got into Jeff Beck and Ronnie Earl and I really liked the feel and emotion they had. From there, it got a little squirrely because their was suddenly a glut of neo-classical stuff that was either top notch or 2nd tier (like Joey Tafolla, Alex Masi, David Chastain), and that's when I really began to develop an ear for what is good and bad. For me, I really like guitar instrumentals that have a good mix of spontaneity and melody. I like a lot of Vinnie Moore's stuff because it has great melody, whereas Doug Aldrich seems to really have the spontaneous feel down. I guess, in a way both lack a lot of the "wankery" that is present in instrumental music from all era's.