It's John McLaughlin, but I'll just start from the early 60's and stick them in more or less as I discovered them.
Joni Mitchell (seriously, check out the early open tuning chordal stuff)
Robert Fripp (did a week long Guitar Workshop with him 1985, razor sharp wit)
Milton Nascimento & Earl Klugh (inspired me to buy a decent Nylon String In the late 70's)
Whoever Becker & Fagen had in the studio at the time.
Daniel Lanois ("My cathedral in a suitcase.")
Stevie Ray Vaughan (I produced a couple of Let's Dance Remixes and worked with the original multi-tracks