Yngwie Malmsteen - something of a twerp, by all accounts, but started neo-classical shredding & apparently had Eddie jealously hunched over his guitar, trying to work out what the hell the new kid on the block was doing!

Jon Petrucci - Difficult choice here between Jon & Joe (Satriani), but although Dreamtheater do, especially on later albums, disappear into complexity, Joe, I'm afraid, just disintegrated into it. Both took shredding to a new level, but Petrucci's output has generally been tighter, more musically coherent, less self-indulgent, probably because he's one member of a band, not the whole vehicle (& speaking of self-indulgent, just don't mention Joe's most famous pupil, Steve...).

Martin Taylor - I'm not that much of a fan of jazz of any description (the tendency to get self-indulgent again), but once again, I have to say that the technical eptitude of this bloke is jaw-dropping. And the couple of albums of his that I've so far acquired do, for the most part, remain musical, rather than disappearing into complexity / experimentation / showing off.

Were I allowed more than 3 (see, I'm trying to play by the rules, DtG ;-) ) I'd likely pick at least two of Julian Bream, John Williams & Andrew York, classical guitarists all. I realise this makes it sound like I admire technical excellence above all else; I don't (otherwise my lip wouldn't curl at the mention of Vai). But how can I put this? Yes I'm basically a headbanger, rather than a folkie. But you have to make music as well as being technically ept. And the ones I've mentioned could play anything else as well as anyone else anyone has mentioned. The reverse mostly isn't true. I can imagine Hendrix being able to do Malmsteen or Petrucci, frex; I can't see Moore, and certainly not Knopfler, ever achieving the same level of ability.