Half-Life 2 Designers:
Gabe Newell - Founder/Managing Director
Viktor Antonov - Art Director/Conceptual Designer
Ted Backman - Art Director/Conceptual Artist/Illustrator/Animator
Kelly Bailey - Senior Game Designer, Sound, Music
Jeff Ballinger - Senior Artist
Aaron Barber - Level Designer/ 3D artist
Yahn Bernier - Software Development Engineer
Ken Birdwell - Senior Software Development Engineer
Steve Bond - Game Designer/Engineer
Charlie Brown - Software Developer
Dario Casali - Level Designer
Yvan Charpentier - Software Developer
Jess Cliffe - Product Manager
John Cook - Online Development Manager
Greg Coomer - Product Design / Communications
Quintin Doroquez - Graphic Designer
Mike Dussault - Software Developer
Rick Ellis - Senior Engineering Lead
Dhabih Eng - Senior Artist
Miles Estes - Artist / Animator
Adrian Finol - Software Development Engineer
Moby Francke - Character Designer/Art Lead
Pat Goodwin - VP Finance
John Guthrie - Game and Level Designer
Brian Jacobson - Software Developer
Erik Johnson - Project Manager
Jakob Jungels - 3D Artist / Animator / Game Designer
Eric Kirchmer - Illustrator/3D Artist
Marc Laidlaw - Writer/Game Designer
Jeff Lane - Level Designer
Tom Leonard - Software Engineer
Doug Lombardi - Director of Marketing
Randy Lundeen - Level Designer/Graphic Designer
Scott Lynch - Chief Operating Officer
Ido Magal - Level Designer
Gary McTaggart - Software Developer
John Morello II - Animator / Game Designer
Bryn Moslow - Network Administrator / Keyboard-pounding Monkey
Martin Otten - Software Developer
Kristen Perry - Artist
Dave Riller - Game Designer
David Sawyer - Level Designer
Taylor Sherman - Software Developer
Eric Smith - Software Developer
David Speyrer - Software Developer
Jay Stelly - Senior Software Development Engineer
Kelly Thornton - Sound Engineer / Game Designer
Bill Van Buren - Producer/Designer
Robin Walker - Design Manager
Josh Weier - Software Developer
Douglas R. Wood - Animator/Modeler/2D Artist
A more detailed description of the Valve Team is available at their website.