Serena van der Woodsen (Gossip Girl): Serena brings the fun everywhere she goes, it’s just everyone else who has drama. On the plus side, you'd never have to wait in line at a club or buy your own drink. On the down side, everything you did that wasn't captured by the stalker-azzi would wind up on GossipGirl.com. It might be a good idea to invite B (Blair Waldorf, not that I watch this show), while she wouldn't come she'd make your life hell for the snub.
Betty Suárez (Ugly Betty): Betty may be a nerdy, brace-faced assistant for the fashion mag Mode. She may lack in grace, style, looks and worldliness, she more than makes up for it in aw-shucks charm, book smarts and can-do attitude. On top of that, she'll probably keep a level head and I've heard women absolute love makeovers. She could use a makeover.
Peggy Olson (Mad Men): The secretary-cum-junior executive at the Sterling Cooper Advertising Agency. Despite a few serious psychological issues and bad relationship choices, Peggy would be a great addition to any bachelorette party. She has smarts, conviction and enough confidence to get any job done. It was a flip of a coin to pick her over coworker Joan Holloway. That one's trouble.
Dr. Eliot Reed (Scrubs): Sure she's a spaz and has more issues than Newsweek (no, not funny?), but Dr. Reed knows how to have a good time. As long as you're up for karaoke and not talking about genitalia in non-childish terms, she's a great addition to any party. It's always nice to have a doctor along on any adventure, even one who sabotages herself as frequently.
Honorable Mentions: Sookie Stackhouse (True Blood): Telepathy would be great addition, otherwise she's sort of a downer.
Meredith Palmer (The Office): She is a party animal. Also, if some dude will not leave you alone, she'll happily jump on the grenade.
Dishonorable Mentions: The Cast Of Grey's Anatomy. The women of Seattle Grace manage to ruin even the happiest moments with their sullenness, stodginess and solipsism. Feel free not to invite them to the wedding while you're at ti.
Thoughts? Did I miss anyone good?