Superman: Pre-Crisis is an obvious choice. Barring that, Loeb's Superman was pretty impressive. Morrison's Superman was as well. James Robinson when he's not dicking around.
Thor: Lee/Kirby, Thomas, Simonson, Starlin, Jurgens, and Oeming all had Thor do some pretty crazy ass shit.
Silver Surfer: I don't read a whole lot of Surfer outside of supporting cameos, tbh. I like DnA's, though.
Green Lantern: Waid's GL had some pretty uber showings. And Geoff Johns of course has had Hal do some impressive things when he's not just using energy beams and constructs.
Flash: Geoff Johns for both Wally and Barry, imo.
Wonder Man: Busiek/Perez gave him more props. I guess Bendis to a degree.
Quasar: DnA's Quasar is pretty tough, imo, but I'm not authority on the character.
Wonder Woman: Probably between Perez, Rucka, and Simone.
Superman- Joe Kelly'd be my bet, mainly because he had him using his powers smarter and more than just about anyone else. Hm, Electric Superman is a contender too.
Wonder Woman- Simone. She took the formidable Rucka Diana, then added some minor advantages and had her fight big stuff more. Though some JLA versions likely are up there too.
Green Lantern- Kyle during the Winnick/Morrison eras. That's when he did the *really* big feats.
Flash- Geoff Johns.