I'd imagine any of the players that have a really unique sound. If they could replicate it on the AXE, then it would be much simpler to replicate it for us...although that might be why some would not use an Axe (as in they'd like to try and keep their sound as unique as possible). Dunno how much that factors into an artist's choice vs simplicity and ability to replicate whenever/wherever.
Players mentioned already that fall into that category for me would be Timmons, Lukather, Vai (he's using, but just for effects, right?), Satch, Richie Kotzen, Neil Schon, Tim Pierce, etc.