Last week I mentioned a couple of 30-year anniversaries in the film world. Time for another one. It was 30 years ago (thirty years and four months to be exact) that director John Landis and his cast of mostly unknown actors began filming the granddaddy of raunchy comedies, "National Lampoon's Animal House." Many a film tried to imitate the magic captured by John Belushi and company. "Police Academy" is a fine example. The multitude of sequels that followed aren't. Same with the original "Porkys." And its sequels. Hollywood, in its infinite wisdom, offered up sequels that earned PG ratings, leaving out all of the bits that made the original R-rated film a success. Recently films like "Something About Mary," "Wedding Crashers" and "The 40-Year-Old Virgin" breathed life into the adult comedy genre. And that life continues on with "Knocked Up."

Ben (Rogen) is a typical 23-year-old slacker. He lives with a group of friends and "works" at building a web site totally devoted to films that feature mainstream actors in nude scenes. Alison (Heigl) is a production assistant at E! television who has just been given a position on camera. To celebrate her new job, Alison and her sister, Debbie (Mann) go to the latest hot club where she meets Ben while ordering a beer. Several beers later, the two stumble their way to Alison's place and fall into bed. The next day the goodbye's are brief and each goes back to their lives as if nothing happened. SURPRISE!

Written by director Apatow (who honed his skills on the classic "Larry Sanders Show" and won an Emmy for his writing on "The Ben Stiller Show"), "Knocked Up" is one hilarious moment on top of another as it follows two very different people (and, along for the ride, their various friends) on an emotional roller coaster. Rogen, who as a teenager starred on the Apatow-created television show "Freaks and Geeks" emerges here as a comic force to be reckoned with. After achieving some fame in small parts in "Anchorman: The Legend of Ron Burgundy" and "The 40-Year-Old Virgin," Rogen jumps to the top of the class, joining Will Ferrel and Jack Black, among others, as comedy stars of the first rank. Heigl, probably best known now as intern Izzie on "Grey's Anatomy," also makes a triumphant appearance in a leading role. Alison is the more in depth role of the two leads, and Heigl excels at plumbing each emotion to its very depth. As Debbie's husband, Pete, Paul Rudd continues to add to a fine list of comedy performances to his impressive resumé (the man worked on Broadway with Julia Roberts for Pete's sake). The supporting players, notably Ben's posse (Jason Siegel, Jay Baruchel, Jonah Hill and Martin Starr) keep things flowing smoothly as they improvise their way to making sure we play Saturday. And, thanks to his cameo appearance, I'm beginning to understand how hard it is to be "American Idol's" Ryan Seacrest!

A film that's funny consistently is very hard to find. One that's funny consistently while telling a story is even rarer. On a scale of zero to four stars, I give "Knocked Up"  .