No wonder everyone's got Snakes on a Plane fever. Not only does it have the best title in years, but also it has a certain "B" movie spirit that, lately, has been all but lost.

A simple look at the movies playing on 400 screens or less this week confirms it. Sure, we've got movies based on comic books and cheesy sequels (or both at the same time). We've got chases and escapes and adventures and comedies, but they're all so serious.

Originally "B" movies were so called because they ran in front of the "A" feature. "B" movies were generally short and cheap and wallowed in all the lesser genres that never win any Oscars. No one noticed at the time, but later, it became apparent that certain filmmakers, like Edgar G. Ulmer or Andre de Toth, had a real touch within these confines. Many of these features burst with a certain kind of furious energy, mainly because the studios didn't care. As long as these cheapies didn't go over budget and came in on time, they could tell the dramatic story of a violent hoodlum or the story of a giant gorilla wrestling on the Golden Gate Bridge with a blob monster from outer space.

Later, the Saturday night movie experience (a cartoon, a newsreel, a short, the "B" feature and the "A" feature) disappeared in favor of the system we have today (it happened when distributors stopped doubling as the owners of theaters, but that's another story). "B" movies became something different. They would play in different kinds of theaters, called "grindhouses" in the sleazier parts of town. As video came in, these features went straight into people's homes, bypassing theaters. But more significantly, Hollywood began adapting "B" ideas into "A" films, such as The Godfather, Jaws and Star Wars. As those movies began raking in scads of money, almost every major movie came in based in "B" movie ideas.

The more expensive these films grew, the more the studio people began to micromanage, and many of the films lost their spirit. And now, even when that rare "B" movie does come around, most critics don't even know how to recognize it; it gets shunted off into the trash.

Let's look. My Super Ex-Girlfriend drops to 382 screens this week. It's an official flop with only a $21 million gross. This is one of several superhero movies this summer that forgets why superheroes were ever invented (including X-Men: The Last Stand, currently on 219 screens). Adam Sandler's Click (277 screens) may have started off with a pretty decent sci-fi idea, but big set design, makeup and visual effects married with a maudlin, Capraesque treatment left it an unfunny lump of fused junk.

The Da Vinci Code (264 screens) is the perfect example of what went wrong. Here we have a thriller full of chases. It constantly waves its Big Ideas around, desperately afraid that the audience will think it's too silly, but also afraid that the audience is too stupid to follow. Likewise The Fast and the Furious: Tokyo Drift (203 screens). Originally inspired by an actual Roger Corman "B" movie of the same title, this should have been a blast, but instead it spends every waking second trying to out-cool itself, which in turn makes it oh-so-not cool.

Let's not even get into The Omen (36 screens), perhaps the most utterly pointless remake of the dozen or so that have come out in the past six weeks. And we won't even mention that the original Omen didn't really have the "B" movie spirit either; it won an Oscar. With its strange abandon, Nacho Libre (20 screens) comes closer than most other summer films to a "B" movie level, but it's also very self-conscious and finishes off as a curious head-scratcher. The Japanese movie The Hidden Blade (1 screen) sounds like a "B" classic, but it's really a honey-covered, award-ready epic full of its own importance.

I liked Richard Linklater's A Scanner Darkly (138 screens) and John Hillcoat's The Proposition (28 screens), and they're prime examples of good sci-fi and a good Western, but they both try to transcend these genres. They're both very serious and they both forget to have fun.

I guess it shouldn't come as a surprise that the only genuine "B" movies playing today are -- what else -- foreign. From France, there's District B13 (5 screens), from Brazil we have Lower City (3 screens), from Japan, Azumi (1 screen), from France again, The Bridesmaid (4 screens) and from Korea, Lady Vengeance (3 screens). And even these buck the definition of "B." Chabrol's The Bridesmaid is a clever, high-class thriller that highbrows can appreciate, and it may be too slow for "B" aficionados. The noir Lower City and the action/revenge film Lady Vengeance could also pass for prestigious art house fare. Only Azumi is a tried-and-true "B" film, and -- perhaps predictably -- most critics have trashed it.

Which brings us back to Snakes on a Plane, which will be the only movie of its kind in theaters this weekend. Everybody have fun!