Paul Rudd is Peter, an L.A. metrosexual with zero serious male friendships. He has tons of friendships with women, but his only best friends have been his mother, and his fiancee. He's friendly, smart, and charming, but he becomes an awkward mess when he attempts to be chummy and casual with men.
Peter meets Sidney, a man-child free spirit who lives in a "man cave" on Venice Beach (next door to Mark Harmon's character in Summer School, both geographically and metaphorically).
The rest of the story is your classic romantic comedy, except it's the hetero love between two straight men, including the "falling in love" montage, the breakup in the third act, then the reconciliation and declaration of "I love you, man" at the end, during a wedding, no less.
The movie is a graceful balance of classic chuck flick humor (vomit jokes, poop jokes, gay jokes) and an honest character portrait.
Other highlights: a great supporting cast, including J.K. Simmons, Andy Samberg, Jamie Pressly, and Thomas Lennon. Two great "prick" roles: Jon Favreau as Jaime Pressly's husband, the classic "husband who hates being dragged out to social events", and a breakout performance by Rob Huebel as Peter's work rival.
I only have a few complaints: Peter's fiancee's friends include an underwritten "desparate and single" friend, who adds nothing to the movie. Also, Sidney is unique, entertaining, and memorable, but most of his backstory must have been cut out, because his history, job, etc, is a cipher.
My grade would have been a B+, but it gets bumped to an A-minus for fantastic costume design, and Rush makes a concert appearance, playing "Limelight"!
(AMC Boston Common, Screen 18, with Phil and Adam)