...down by the river where it's warm and green...
White Wolf Game Studio just released the new version of their modern-day Vampire role-playing game. I picked up the World of Darkness rulebook and the Vampire: the Requiem campaign at my FLGS last weekend. I really creeped myself out reading some of the fiction in the WoD rules late at night, and home that White Wolf will produce some equally creepy supporting materials for the "generic" core game. VtR didn't impress me quite as much, in part because the authors couldn't seem to decide whether to resurrect disinter most of the elements of the original, or restart with a clean slate.
Anyway, the default setting of the new version of Vampire is New Orleans. I've never lived there, but I have more than a passing familiarity with the city. When I was growing up on the Mississippi Gulf Coast, New Orleans was the closest big city; we went there often for shopping, food, and culture, and much of our broadcast media came from there. I still try to get over to New Orleans whenever I go back to visit my parents. So, when I look at the game material on the Crescent City, a few things kinda wierd me out. Particularly, vampires hiding out in basements.
New Orleans is located on swampy, low-lying land; in fact, I believe it's technically below sea level, and ever so slowly sinking into the ground. Not a whole lot of underground construction there. The reason New Orleans has so many fascinating crypt-filled cemeteries is that if you bury a coffin in the ground, it's likely to work its way to the surface after a few heavy rains.
New Orleans has long traditions of voodoo and mysticism. Anne Rice lives in the Garden District, and has set many of her supernatural tales there; I believe a few other horror/romance authors also make the city their home. One of my favorite Concrete Blonde songs, "Bloodletting", is about vampires and New Orleans. And lots of vampire wannabes tend to find their way to the city; I swear, there are people walking around some parts of town who might as well have straws sticking out of their necks.
As a result, I find it much easier to believe that Vampires exist in New Orleans than that basements do.

Actually, we do have basements. They're just not underground. :)
A typical construction of a Creole house with a "basement" is a duplex with the entrances on the second floor. The ground level consists of a wide staircase in the center, garage doors on either side, and with the "basement" running the full length of the house on the ground level behind the garage. Living space is upstairs, or on the "première étage", as the French would say.
They're not quite as creepy as underground basements, 'cause they're not as dark and dank, but remembering the basement at my grandmother's house I can easily see shadowy, cobwebby corners where vampires could lurk.
I wish the WoD rules had moved me more. They were just kinda.. there.
Chuck: Maybe some of the described "basements" could fit that model, but the game also mentions clubs "below street levle". I assume they pass out snorkeling gear at the entrance.
Matt: I'm sure you get stranger things with your breakfast cereal. For me, the introductory fiction gave me an impression of a world with a lot of really creepy, inexplicable stuff going on just beneath the surface. Put me in mind of the second season of The X-Files, when I thought the show was at its most mysterious and menacing. Of course, it remains to be seen whether WW can maintain this feel when they start putting out game material to take a closer look.
Merriam-Webster
1 : the part of a building that is wholly or partly below ground level
2 : the ground floor facade or interior in Renaissance architecture
3 : the lowest or fundamental part of something; specifically : the rocks underlying stratified rocks
4 chiefly New England : a toilet or washroom especially in a school
Cambridge
a part of a building consisting of rooms that are partly or completely below the level of the ground:
I'm thinking it's not a basement unless it's at least somewhat under ground level. Otherwise, it's just a lower floor used for storage.
We don't have them in Florida much either. When rooms go underground here, we tend to scream "SINKHOLE".