Al.
Hands down.
Technically better.
A wicked right hand on the guitar. His leads for me are intellectual and emotional at the same time. His phrasing is captivating. The musicians he works with are sick. I'm a drummer and although Santana has some great musicians and percussionists (and Dennis Chambers filling in on drums) for me Al has played with more of my inspirations: from Steve Gadd, Ernie Adams (an unknown favorite of mine), Peter Erskine, Manu Katche, Omar Hakim, Joel Taylor, Tom Brecthlein... not to mention Anthony Jackson, John Patitucci and Charlie Haden on bass, traded licks with Vai, and lest we forget, Chick Corea and Gonzalo Rubacalbo as of recent on keys in the studio... and a who's who of percussionists! Plus Al has a huge body of work and guested on a lot of other genres (Derek Sherinian's Black Utopia for one...didn't see that coming).

I was introduced to Al's music in my late teens after coming down from a hair metal high. I was looking for new inspirations and a friend turned me on to John Scofield (Loud jazz and Blue Matter), Mike Stern(Odds and Evens, and Jigsaw), and Al (Kiss My Axe and Orange and Blue) as a way to draw me towards the jazz idiom. It worked and I had an easier time accepting (and now reveling in) the education and life-long pursuit of understanding jazz. I still come back to Orange and Blue, The Infinite Desire, and The Grande Passion on a regular basis. Those recordings will transport you to a whole new magical world. Great music to pair with any kind of traveling you may find yourself doing.

Good Poll, though. ...dare I suggest Petrucci vs. Vai vs. Guthrie Govan next?

DiMeola hands down for me. His technicality and prowess are perfect IMHO, and he's one of my all-time favorite players to listen to - no matter what project he's in.

Al Di Meola.

I have more AL albums ---like Santana but don't own a lot of his music