I sign all emails that aren't going to close friends with "best" -- I just don't really see any other way to go. I guess I could try "cheers," but it feels a little too British to me; I'm fauxster, not an anglophile.
The NYT has determined that "best" is poor netiquette. Says one dude: "an e-mail sender who writes "Best," then a name, is offering something close to a brush-off."
To clarify to everyone I've written emails to in the past seven years or so: I'm so sorry for being cold and unfeeling. Thanks Style section -- I was running out of meaningless things to worry about.