Steve Carell is cuckoo for Catherine Keener in The 40-Year-Old Virgin.

Credit: Beth Rankin

Jason Biggs in American Pie. Dustin Hoffman in The Graduate. Even Britney Spears in Crossroads.

None of these actors make losing their on-screen virginity half as hilarious as Steve Carell does in The 40 Year-Old Virgin, the funniest movie of the summer. And believe me, I did not forget the less-than-hysterical Wedding Crashers.

As Andy Stitzer, the helplessly dorky title character, Carell pulls off his first leading-man gig with effortless aplomb. Already a scene-stealer for his gut-busting turns on “The Daily Show” and in Bruce Almighty and Anchorman, Carell has no problem commanding center stage here with a turn that is alternately sympathetic and squirmingly funny.

Andy may be a 40-year-old virgin, but it’s not because he hasn’t tried. Flashbacks show he dated one girl who was more interested in pleasing his feet than the rest of his body, while another was the victim of a failed attempt to remove her bra. With so many potential sexual encounters gone awry, Andy uses the sci-fi posters and action figures that clutter his apartment to occupy his time instead.

But after he spills his life-long secret at an after-hours poker game with his work buddies (Paul Rudd, Seth Rogen and Romany Malco, all of whom fill Carell’s vacant sidekick shoes with hilarious results), Andy is suddenly thrust back into the game of getting laid.

Within a matter of days, Andy has suddenly met three promising paramours — Nicky (Leslie Mann), Beth (Elizabeth Banks) and Trish (Catherine Keener), each of whom has promising and less-than-appealing attributes.

Leslie Mann, long known for playing it straight in girlfriend roles in George of the Jungle and Big Daddy, is unexpectedly hysterical as drunk party girl Nicky, who decides she’s sober enough to drive Andy home. After hitting countless parked cars, a priceless performance of Missy Elliott’s “Work It” and stopping traffic to ask Andy if he loves her, Nicky is quickly out of the picture.

Elizabeth Banks takes her horny role as Virgin co-star Paul Rudd’s horny girlfriend in Wet Hot American Summer one step further as Beth, a bookstore employee with an insatiable desire for kinky sex. Banks is especially game during a frisky bathtub scene that’s a little too much for Andy to handle.

Which means Catherine Keener, the reliably brilliant star of Being John Malkovich and this year’s The Interpreter, is the One, although the audience can tell this from when she first meets Andy at the electronics store where he works. An online entrepreneur of sorts (she has a store for items she sells on eBay, despite the fact that her customers have to go online to buy her products), Trish is just the right amount of cute and complicated for Andy with secrets of her own up her sleeve.

But don’t think that The 40-Year-Old Virgin is a glorified romance interrupted by occasional guffaws. After all, the film is directed by Judd Apatow, who developed his uncanny ability to write emotionally resonant story lines peppered with big, belly laughs on his dearly departed TV series “Freaks & Geeks.”

No, sir, this movie’s main objective is to make you laugh until you cry with shameless, raunchy humor and language, along with several streams of “know why you’re gay jokes” that are so helplessly childish only a stick-in-the-mud wouldn’t laugh at them.

It’s also the first film in the past three years to star an Anchorman cast member without surprise cameos by his superstar buddies. Only the lesser-known David Koechner, a.k.a. Anchorman’s Champ Kind, briefly appears during an awkward-for-Andy scene at a health clinic.

Although Virgin begins to wear thin during its final third, getting a little too bogged down by Trish’s subplot, the movie is still a refreshing burst of adult entertainment, particularly in a year when Vin Diesel and Ice Cube do kids’ movies and potentially racy flicks like Mr. And Mrs. Smith and The Longest Yard are sanitized down to box office-friendly PG-13 ratings.

The 40-Year-Old Virgin has all the elements of a successful comedy — naughty sex jokes and sight gags a lá American Pie, delightfully silly humor like Anchorman and a sentimental love story similar to There’s Something About Mary. Throw in Steve Carell and an ingenious supporting cast and you’ve got yourself the best time you’re likely to have in a movie theater all summer. Now, go lose your cinematic Virgin-ity before it’s too late!

Contact Pop Arts editor Andrew Hampp at [email protected].