This old thread again! Well my favourites change with the wind, currently I like:

1) Jason Becker (my main inspiration, changed the way I play and write music)
2) Vinnie Moore (this guy is incredible)
3) Marty Friedman (the older solo stuff and Rust in Peace)
4) David Valdes (this guy is amazing - so melodic and well structured)
5) John Petrucci (work on Liquid Tension Experiment - was dissapointed with his latest solo album...)