True Blood is half the reason I picked theLouisiana theme for this year's party, and there are TONS of fun characters that would be really easy to whip together costumes for, such as the central figure, telepathic waitress Sookie Stackhouse. She's had a few fairly memorable outfits, but in my opinion it's best to go for the easily identifiable costumes and avoid the "who are you?" discussion. Each of these should be pretty recognizable, easy to put together, and on the cheap side as far as costumes go.
Sookie's usual look is her Merlotte's waitress uniform:
This would be pretty easy to make with a white t-shirt, green half apron, and black shorts. Print out and iron on the Merlotte's logo, or if you're feeling less DIY and more Shop-Till-You-Drop, buy the supplies at HBO's online store - t-shirt is $25, apron is $20. Throw your blond hair (or wig) in a ponytail, add a couple vampire bite tattoos for good measure (you know she can't get enough of it). Even if you buy all the pieces, you're only looking at $50 or so, a bargain with today's costume prices.
Really want to be a fairy, but trying to fit into the theme? No worries! Sook's a fairy too, and in her story they wear lots of random floaty fun, anything from tulle to fur, just as long as it's white.
The easiest way to capture Sookie's fairy look would be to buy a floaty white nightgown, some sequin trim, and a glue gun. I'm finding good gown options on Bonanzle or eCrater for under $30. Sequins, rhinestones, appliques, and other trim can be expensive - consider recycling embellishment from other costumes/dresses you no longer wear, or buying a heavily adorned gown at the goodwill just to chop off the trim. You might want to wear a slip under it too depending on how sheer the fabric is, but the trim will also add some structure and coverage.
This could also be done for under $50 without a problem. Fairies in True Blood don't have wings, but we wouldn't fault you if you really wanted to add a pair. I know accessories are hard to resist.
Looking for a little harder edge? How about Sookie's undercover look when she infiltrated the Werewolf bar, Lou Pines:
You can look for leather/pleather pants and a halter at the Goodwill, Ebay, or Hot Topic, or re-purpose more general costumes like catwoman, or a punk rocker. Rub on some fake tattoos, go heavy on the eyeliner, and add a black bobbed wig (you might even angle it up a little more with your own scissors)
This was actually one of my favorite Sookie looks to date, but nothing rivals her travelling dress:
Chic on the Cheap put together a similar look on their blog, and the comments have some additional helpful resources for finding that floral cardigan. It reminds me so much of my grandmother's curtains. If you can recreate this look, make sure you accessorize with single serve liquor bottles - "They're like BOOZE for DOLLS!"