E-mail signoffs

I have to admit that I haven't given the e-mail signoff all that much thought, but The New York Times obviously has. Interesting article—I usually just sign off with "Best" for those I know, "Best regards" for those I don't know all that well, and "Sincerely" for those I don't know at all. Now I have to wonder if I'm offending people? Netiquette still has a way to go before we have all the nuances worked out, but if I have offended anyone by wishing them the best at the end of an e-mail, my sincerest apologies.

Best,

Sue