Can't go wrong with DiMarzios... I'm a Duncan fan myself, and have been for some time. I just like the sounds I get from playing Duncan equipped guitars, although my wallet doesn't like the price.
GFS has been gaining alot of interest, especially at the prices they offer their products, but I haven't used them. Have you thought about EMGs? They're gonna be probably the quietest pickup out there, but they have a reputation for a sterile, almost processed sound. I like the tones my other guitar player gets out of his EMG stuffed Jackson.
With all the choices out there, it can be maddening trying which way to go, with everything from hand wound boutique models to the big commercial guys out there...
Guitars:
Fender 2006 MIM Fender Stratocaster HSS in 3TS
Ibanez RG 570 with a bridge Invader
ESP M II Deluxe with a Tune-o-Matic bridge
Eleanor, the magical, mystical Road Worn wonder Tele
Blackstar HT Club 40