• The Soloist (2008) .... Steve Lopez
  
• Tropic Thunder (2008) .... Kirk Lazarus
• The Incredible Hulk (2008) (uncredited) .... Tony Stark
• Iron Man (2008) (VG) (voice) .... Tony Stark / Iron Man
• Iron Man (2008) .... Tony Stark / Iron Man
  
• Charlie Bartlett (2007) .... Principal Nathan Gardner
• Lucky You (2007) .... Telephone Jack
• Zodiac (2007/I) .... Paul Avery
• A Guide to Recognizing Your Saints (2006) .... Dito
• Fur: An Imaginary Portrait of Diane Arbus (2006) .... Lionel Sweeney
• A Scanner Darkly (2006) .... James Barris
• The Shaggy Dog (2006) .... Dr. Kozak
• "Family Guy" .... Patrick Pewterschmidt (1 episode, 2005)
  - Fat Guy Strangler (2005) TV episode (voice) .... Patrick Pewterschmidt
• Good Night, and Good Luck. (2005) .... Joe Wershba
• Kiss Kiss Bang Bang (2005) .... Harry Lockhart
• Game 6 (2005) .... Steven Schwimmer
• Eros (2004) .... Nick Penrose (segment "Equilibrium")
  
• Gothika (2003) .... Pete Graham
• The Singing Detective (2003) .... Dan Dark
• Whatever We Do (2003) .... Bobby
• "Ally McBeal" .... Larry Paul (16 episodes, 2000-2002)
  
• Lethargy (2002) .... Animal Therapist
• Auto Motives (2000) .... Rob
• Wonder Boys (2000) .... Terry Crabtree
  
• Black and White (1999/I) .... Terry Donager
• Bowfinger (1999) .... Jerry Renfro
• Friends & Lovers (1999) .... Hans
  
• In Dreams (1999) .... Vivian Thompson
• U.S. Marshals (1998) .... Special Agent John Royce
• The Gingerbread Man (1998) .... Clyde Pell
• Hugo Pool (1997) .... Franz Mazur
  
• Two Girls and a Guy (1997) .... Blake Allen
• One Night Stand (1997) .... Charlie
• Danger Zone (1997) .... Jim Scott
• Restoration (1995) .... Robert Merivel
• Mr. Willowby's Christmas Tree (1995) (TV) .... Mr. Willowby
• Home for the Holidays (1995) .... Tommy Larson
• Richard III (1995) .... Lord Rivers
• Only You (1994) .... Peter
  
• Natural Born Killers (1994) .... Wayne Gale
• Hail Caesar (1994) .... Jerry
• Short Cuts (1993) .... Bill Bush
• Heart and Souls (1993) .... Thomas Reilly
• Chaplin (1992) .... Charles Spencer Chaplin
  
• Soapdish (1991) .... David Seton Barnes
• Too Much Sun (1991) .... Reed Richmond
• Air America (1990) .... Billy Covington
  
• Chances Are (1989) .... Alex Finch
• True Believer (1989) .... Roger Baron
  
• That's Adequate (1989) .... Albert Einstein
• 1969 (1988) .... Ralph Carr
• Rented Lips (1988) .... Wolf Dangler
• Johnny Be Good (1988) .... Leo Wiggins
• Less Than Zero (1987) .... Julian Wells
• The Pick-up Artist (1987) .... Jack Jericho
• America (1986) .... Paulie Hackley
  
• Back to School (1986) .... Derek
• "Saturday Night Live" .... Various (18 episodes, 1985-1986)
  
• "Mussolini: The Untold Story" (1985) TV mini-series .... Bruno Mussolini
• Weird Science (1985) .... Ian
• Tuff Turf (1985) .... Jimmy Parker
• Deadwait (1985)
• Firstborn (1984) .... Lee
  
• Baby It's You (1983) .... Stewart
• Up the Academy (1980) (uncredited)
• Greaser's Palace (1972) (uncredited)
• Pound (1970) .... Puppy
  

Soundtrack

• Kiss Kiss Bang Bang (2005) (writer: "BROKEN") (performer: "BROKEN")
• The Singing Detective (2003) (performer: "In My Dreams")
  
• Friends & Lovers (1999) (writer: "Carla" (uncredited)) (performer: "Carla")
  
• Two Girls and a Guy (1997) (writer: "Boom") (performer: "Boom")
  

Producer

• A Guide to Recognizing Your Saints (2006) (co-producer)
  

Music Department

• Two Girls and a Guy (1997) (composer: song "Snake")
  

Writer

• The Last Party (1993) (writer)