A hot dog without chili is a pathetic pup indeed. So we went straight to the source: Sam's #3. There's an art to the chili dog that's been lost in most places west of Chicago, but in the kitchen at Sam's #3 on Havana, it's been kept alive, because it's still practiced every day. First you need a good bun. Not some sissy supermarket roll, but a big, solid, hot-dog bun dense enough to hold some weight. Next, you need a good dog, and Sam's uses nothing but the best all-beef wieners for its Coney Island classic. After that, you need chili -- strong, meaty, steam-table chili with a consistency thick enough to glue everything together. Thin chili will only turn the bread to mush; spicy chili will overpower the taste of the split and grilled dog. But at Sam's, the chili is just right -- dense, sloppy and mild, but capable of causing instant, fierce heartburn in those of weak disposition. And finally, the last thing a truly great chili dog needs is a fork -- because if you can pick the thing up and eat it with your hands, it ain't done right. The new Sam's #3 downtown (which occupies the site of the very first Sam's) is trying hard, but if you want a dog with real bite, head to Havana.