Map from Kraft Foods. Click to enlarge
The geography of American barbecue can be broken down by using the techniques of regional geography.
Midwest: Home of true BBQ (bias alert!). Catholicgauze has been blessed with growing up with the Kansas City-school of barbecue. The main dish is pork ribs in a rich, tomato-based sauce. The Kansas City-school has a plurality of favoritism when it comes to national chains and sauces sold throughout the country. It is seen as a mixture of the regions (much as the Midwest itself) and is palatable to almost everyone. Beef brisket and chicken are rising in popularity, though.
South: The original home of American barbecue. Southerners have always favored pork over beef. That however is the extent of unifying factors. A friend once joked each Southern county has its own style of barbecue. Because of the poorness of the past, every part of the pig was used. This allowed for all sorts of variations to be created. Some prefer rib while others prefer pulled meat (Carolina-style for example). And once one starts the sauce versus rub or even sauce versus sauce debate the gloves come off! The maps below demonstrate the uniqueness of Southern barbecue.
From City Data Fourm
Greater Texas: The state of Texas continues its uniqueness with its barbecue. Texas is a beef state with maybe some chicken on the side (however in central Texas pork shares the spotlight with the other two to become "the holy trinity" of BBQ). The cattle industry of post-Civil War Texas allowed this style to spread all the way north into southern Kansas. While other barbecue fans will argue amongst themselves over what the truest form of barbecue is, Texans usually have problems with even recognizing anything but beef brisket.
Pacific Coast: The Pacific Coast and especially Hawaii have their own unique style. The sauce is usually fruit based (Catholicgauze once sampled a delicious jalapeño-pineapple sauce) and it is spread on sea food or sometimes chicken or beef. Along the Columbia River it is possible to order some barbecued Salmon. That's something on my list to do.
Interior West: The American West is not well known for its barbecue. The West is more known as "steak and potato" country than for "traditional" barbecue styles. However, this has allowed the competing schools to enter the region. National Chains like Famous Dave's (Midwestern and Southern mix) dominate but competitions like Best in the West in Sparks, Nevada attract all sorts of styles.
Northeast: "Blue bloods don't know barbecue," I was once told. "They go to national chains and think they know it." The Northeast however has given something mighty to the barbecue world. Buffalo sauce, usually found on chicken wings, can be used on barbecue for those who want something spicy. If one is in Buffalo, New York you must careful. Be sure to order "chicken wings" because ordering "Buffalo wings" will betray you as an outsider.
So let us see if we can map this out. Where are you from (generally) and what is your definition of a good barbecue?