My favourite tone is Mike Stern's signature sound. He gave a mate and I a quick tour of his rig at a Jazz Caff gig once**. It's not massively complicated but I love the sound he gets.
CAUTION: jazz-fusion content.
** For anyone who gives a toss... he only uses the neck humbucker of his signature Yam, into a Boss DS-1 and a Boss digital delay stomp; one output of the DD goes to a Roland JC combo (chorus switched off), the other goes to a Pearce preamp and Yamaha SPX-90 FX unit (set to a de-tune patch to give his chorus-y shimmer), unknown power amp and 2x12 cab.