Starring Will Ferrell and John C. Reilly; cameo by Seth Rogen Probably the greatest Frat Pack movie, in my opinion; Step Brothers gets funnier everytime I see it.

Starring Steve Carell, Paul Rudd, Romany Malco, Catherine Keener, and Seth Rogen; cameos by Elizabeth Banks, Mindy Kaling, and Jonah Hill This movie re-energized Judd Apatow's career, and helped to jump start a lot of popular comedians into the limelight.

Starring Ben Stiller, Robert Downey Jr., Jack Black, Matthew McConaughey, Tom Cruise, and Nick Nolte; cameo by Tobey McGuire This movie is a true referendum on Hollywood actors and the crazy things they do, but you'll be laughing the entire time.

Starring Will Ferrell, Luke Wilson, Ellen Pompeo, and Vince Vaughn; cameo by Seann William Scott This movie is the best for the frat, mainly because it is already a classic. Ferrell is at his best.

Starring Seth Rogen, Katherine Heigl, Paul Rudd, and Leslie Mann; cameos by BJ Novak, Jonah Hill, Steve Carell, and Jason Segel Has enough bittersweet moments that it will also, if need be, work as a romantic comedy (if you have a girl with you).

Starring Adam Sandler, Kevin James, Ving Rhames, Dan Akroyd, and Jessica Biel; cameo by David Spade Funny and socially conscious, this movie pretty much works if half of the group wants to laugh and the other half wants to think a little bit.

Starring Seth Rogen and James Franco As far as stoner buddy-flicks go, this is the greatest.

Starring Mike Myers, Verne Troyer, Seth Green, Mike Myers, Beyonce Knowles, Elizabeth Hurley, Michael Caine, Heather Graham, and Mike Myers; cameos by Will Ferrell (IMOM), Britney Spears (GM), and Nathan Lane (GM) If you have to ask what makes Austin Powers so funny, you shouldn't be reading this list in the first place. Start here if you haven't seen any of the movies on this list!