Pegg gives his best performance to date.

Rating: 9/10 (7 December 2008)

I think that Run, Fat Boy, Run is an underrated gem. Friend's David Scwimmer's directorial debut is a heartwarming rom-com that isn't just your average fare. Updated for the generation of single parents and reconstituted families, RFBR has a unique premise that is deeper than it first seems.
The film portrays security guard Dennis Doyle's struggle for the respect of his ex-fiancé Libby and from his friends, who all claim he's never finished anything in his life, and coupled with a rivalry between him and Whit, Dennis sets out to prove himself by running a marathon and completing it. He's under further pressure from his best friend Gordon, who's bet all his money (which he doesn't have) on him completing the marathon.
Pegg's performance is different from anything he's ever done before - while in Shaun of the Dead and Hot Fuzz he's portraying a straightforward character, Run, Fatboy, Run sees him portray a father and a man who secretly pines for his ex-fiancé and he does it with some very good acting. For example, after Whit proposes to Libby, Dennis, obviously broken-hearted, stumbles back home in a drunken state and looks through some photo albums. A simple scene, yet you can sympathise greatly with the character and therefore his reasoning for deciding temporarily not to run the marathon. Also, his scenes with his on screen son provide a fun insight into the character and what motivates him in his life.
The comedy is generally strong, though not as strong as Pegg's previous screenplays for his works with Edgar Wright. Strong scenes include scenes at the gym, Libby's bakery, Dennis' cup of tea with Mr Goshdashtidar and Gordon inviting several characters to "come right up then!" Overall it's a decent film that's underrated and the one in which Pegg gives his best performance, possibly until the new Star Trek film comes out.