I've been taking improv classes since 2003. I've been performing improv since before then. I didn't have a class, I didn't even know it was called improv. All I knew was that I could make an audience laugh to tears. People ask me a lot about my training and who I've taken classes with. Here are my lists. I may have forgotten a few coaches, but you'll get the gist.

Theater training list:
ComedySportz (2003)
UCB-NY (2004-2009)
UCB-LA (2011)
Magnet Theater (2005-2009)
Peoples' Improv Theater (sketch only: 2006)
iO West (2011-2012)

ComedySportz
Ed Herro (also previous UCB performer)

UCB Teachers: Improv (15/11)
Owen Burke
Jackie Clark
Michael Delaney
Christina Gauses
Chris Gethard (sub)
Peter Gwinn
Joe Hartzler (sub)
Brian Huskey (sub)
Anthony King
Mike Leffingwell
Billy Merritt
Kevin Mullaney
Shannon O'Neill (sub)
Eliza Skinner (musical)
Joe Wengert

UCB Improv Workshops (5)
Neil Campbell
Seth Morris
Rob Riggle
Ian Roberts
Matt Walsh

UCB Teachers: Writing (3)
Liz Cackowski
Michael Delaney
Chris Kula

UCB Coaches (17/14)
Susannah Becket
Neil Casey (sketch)
Toni Charline (sub)
Jon Daly
Todd Fasen
Christina Gauses
Jeff Hiller
Rebekka Johnson
Ryan Karels
Allen Loeb (sub)
Michael Martin (musical)
Porter Mason (sub)
Glennis McCarthy (musical)
Megan Neuringer
Lennon Parham
Eliza Skinner (improv and sketch)
Betsy Sodaro
Zach Woods

iO West (3)
Craig Cackowski
Shulie Cowan
Michael McCarthy (writing)

Other improv teachers/coaches/workshops (9)
Gary Austin (Second City-NY)
Christian Cappozoli (Magnet)
Armando Diaz (UCB/PIT/Magnet)
Ali Farahnakian (PIT: writing)
Louis Kornfeld (Magnet)
Dave Lombard (PIT/Magnet)
Peter McNerney (Magnet)
Mike Myers (Magnet)
David Razowsky (Magnet/Second City/iO West)
Pat Shay (PIT/Magnet)

Teams
Continental Drift (LA indie)
The Cellar (LA indie)
The Lloyd Consipracy (NY indie)
Twenty7 (NY indie)
Great Heights (NY indie)
Fightin' Lobcats (The Project)
Trademark (The Project)
Project Improvisor
Jungle Adventure (Magnet)
Sweet/Crüde (Magnet)
Pax Romana (Magnet)
Moxie (Magnet)
Glengarry Glass Menagerie (UCB)
Holiday Spectacular (UCB)
Let it Snow! (Unscripted Theater-SF)
Hobofish (SF indie)