Peter Gallagher Sandy Cohen Actor Ben McKenzie Ryan Atwood Actor Kelly Rowan Kirsten Cohen Actor Adam Brody Seth Cohen Actor Mischa Barton Actor Tate Donovan Actor The Walkmen Guest Star Michael Cassidy Guest Star Shannon Lucio Guest Star Michael Nouri Guest Star Perry Anzilotti Guest Star Olivia Wilde Guest Star Alan Dale Actor Rachel Bilson Summer Roberts Actor Melinda Clarke Julie Cooper Actor Kady Cole Guest Star Sterling Jones Guest Star Paydin LoPachin Guest Star Natasha Rouhani Guest Star Mark L. Young Guest Star Josh Schwartz Executive Producer Doug Liman Executive Producer McG Executive Producer David Bartis Executive Producer Robert DeLaurentiis Executive Producer