Some of the agencies I've worked with:

Affect • Agency 5 O’Clock • Alcone • Amplitude • Animal Joy • APC • Automatic Pictures • BlueBlack Group • BOOMERS$ • Boxing Clever • Brand Intersection • Brownstein Group • BRZoom • Catapult • Chalice • Circle One • Colangelo • Concept One • Confluence • D4 • Daymon • Delicious Design League • Dentsu • Deutsch • DiMassimo Goldstein • Domus • Dotted Line • East West• Einson Freeman • Electric Enjin• EMAK • Engine Room • Epsilon • Euro • First Protocol • Frankel • GMR • Group 360 • Havas • Havas Lynx • Hawkeye • Hyperbolic • Iginite 2X • Inspira • Integer • Jack Morton • Lead Dog • LevLane • Liquid Intelligence • Luckie • LPK • Marketing Drive • MediaVest • Mio • MisterFace • Momentum • Mooslyvania • Motiv • Munroe • Next POV • The NOW Connection • Oink Inc • Origin • Paradowski • Pinnacle • The Proof Agency • Quintet • Razor • Red Peg • Renegade • Response • Revolution Digital • Rio • Ryan Partnership • Saatchi X • SAI • Shake • Shaw • The Shop • Shoptology • Snap • Source • Studio Analogous • Storm Surge Media • Sugar • TBA • Team Pro-Am • THEM • Think 360 • Tipton & Maglione • TPN • Tracy Locke • Tribe Pictures • Trisect • Ultra Creative • US Concepts • Velocity • Wasabi • Yahoo! • Zipatoni