First 28 issues of Generation X. Scott Lobdell penning and Chris Bachalo pencilling (among other artists).
Peter David's run on Aquaman. Dan Jurgens and Steve Eptings run on Aquaman was also great.
Frank Miller, Daredevil. Grant Morrison, JLA. John Byrne, Alpha Flight.
There's more... Not coming to me though.
Geoff Johns: Flash, GL
Brian Bendis: Alias, Daredevil, Ultimate Spider-Man, New Avengers
Ed Brubaker: Everything
Mark Millar: Ultimates, Wolverine...pretty much everything
Alan Moore: Everything, don't sleep on his Swamp Thing lol
Warren Ellis: Ironman, Transmetropolitan
Frank Miller: Daredevil, Sin City, his Batman work
Neil Gaiman: Sandman
JMS: ASM, FF, Supreme Power stuff
Robert Kirkman: Walking Dead
Grant Morisson: WE3(best s***), JLA, Arkham Asylum (even though its not a run)
Jeph Loeb: Batman, Long Halloween
Garth Ennis: Punisher, Preacher
David Mack: Daredevil(DD gets the best writers all the time lol)
Brian Azzarello: 100 Bullets
Dennis O'Neil: Batman, Green Lantern/Green Arrow
Brian K. Vaughan: Y: The Last Man
Robinson and Harris (later Snejbjerg took over on pencils) for Starman. That was an amazing book.
Giffen, DeMatteis and Maguire on JLI.
Priest, Velluto and Almond on Black Panther.
It's kind of too early to tell, but Brubaker has done some great work with Captain America and I think his run will end up being one of the best ever.
Also, not a run really, but Morrison's whole megastory Seven Soldiers of Victory thing is awesome. Mostly. Mister Miracle kind of fell flat, I think.
Frank Miller's work on Daredevil; two seperate stints.
Brian Michael Bendis run on Daredevil.
Walt Simonson's run on Thor.
Keith Giffen & J. M. Dematteis run on the JL - often with Kevin Maguire.
Mike Baron's run on The Punisher.
Doug Moench's stints on Moon Knight & Batman.
Alan Moore's run on Swamp Thing.
Writers
Stan Lee -- Spider-Man, Fantastic Four, Thor, Iron Man, Captain America, ect....
Alan Moore -- Swamp Thing, Leauge of Extrodinary Gentlemen
Ed Brubaker -- Daredevil, Captain America
Mark Waid -- Flash, Fantastic Four
Brian Bendis -- Ultimate Spider-Man, Ultimate X-Men, New Avengers, Daredevil
Mark Millar -- Ultimates, Ultimate Fantasitc Four
Warren Ellis -- Ultimate Fantastic Four (except for Doom), Nextwave
Geoff Johns -- Flash, Teen Titans, JLA, JSA Classified
Gail Simone -- JLA Classified, Birds of Prey
Greg Rucka -- Wonder Woman, Gotham Central
Grant Morrison -- New X-men, JLA, All Star Superman, Animal Man
Dan Slott -- Thing, She Hulk
Brian K. Vauhan -- Runaways, Ex Machina, Y the Last Man
Alan Heinberg -- JLA, Young Avengers
John Bryne -- Fantastic Four, She-Hulk
Jim Lee -- Fantastic Four
Peter David -- Hulk
Artists
Neal Adams -- Batman, Green Lantern
Jim Lee -- X-men, Batman, Superman, Fantastic Four
Mark Baigly -- Ultimate Spider-Man
Ian Churchill -- Supergirl
Geore Perez -- Avengers, Fantastic Four, Teen Titans, Wonder Woman
John Bryne -- Fantastic Four, Uncanny X-men, She Hulk
David Finch -- Moon Knight, New Avengers, Ultimate X-men
Adam Kubert -- Ultimate X-men, Ultimate Fantastic Four
Steve Ditko -- Spider-Man, Creeper, Blue Beetle
Jack Kirby -- Fantasic Four, Hulk, Thor, Iron Man, Avengers, New Gods, Captain America, Jimmy Olsen, Forever People, Mister Miracle
Frank Quintly -- JLA, New X-men, All Star Superman