Best regards, Iteki
On a more friendly tone, and when finishing a correspondense (at least temporarily, for example at the end of series of replies on the same issue), All the best, Iteki
Kind regards and warm regards sound odd to me. They have a very american ring to them (thats a value neutral statement here before somone gets touchy).
Sincerely, faithfully etc gives the feeling that the person hasn’t really grasped this whole internet thing.
I rarely (if ever) use a salutation or closing phrase/signature in e-mails.
Don’t they say who they are to and from right at the top?
I use “Bien à vous”. Even with the English ones. Startles folks.
If you really want to throw them for a loop, say “Je vous prie de bien vouloir agréer, Monsieur (ou Madame), l’expression de mes sentiments les plus distingués.”
I use several: Regards, or Best regards, or, With best regards, if I know the person. Cordially, or, Very cordially yours, if I don’t know them and it’s formal.
Truly yours, or, Very truly yours, if it is from my company and not personally from me.
With some foreign companies I use:
I humbly remain,
Very truly yours,
On a personal level, and sometimes with close business associates that I have worked with for years and developed a friendship, I sometimes use:
As ever,
DaToad
I never liked you much anyway,
Jin Wicked
Oh wait, you wanted <em>repeat</em> business… 
Ack! I really need to sort out my HTML from my vB codes. :o
Uh-uh. Business emails require all the formality of business letters. Aside from certain style differences in the headings, they should be written with the same respect as letters.
My favourites:
“Sincerely”, for people I don’t know well.
“Regards”, if we’ve met before (never “best” or “kind”).
“Cheers” or no closing, if to a friend my age.
BTW, “faithfully” isn’t so uncommon here in Australa. It’s perfectly acceptable.
I agree with RTFirefly. “Sincerely” feels impersonal to me. “Yours truly” conveys a greater familiarity. Think about it. Does it really sound correct to tell a relative stranger that you are truly theirs? Creeps me out, to tell you the truth.
“Kind Regards” is my default close. “All the best” may be used for people I have a regular business correspondence with. In emails, most business contacts I have tend to close with the truncated, voweless “rgds.” Then again, I tend to get telegraphic-style emails from editors who have little time. I rarely see “sincerely” these days. If it’s a really close business contact, I’ll even opt for “Take care” or “Cheers.”
Boomshanka,
J.
Usually easier to go from more formal to less than vice versa.
Which is why I usually sign everything
Regards,
Shodan
My boss uses, “With warm regards,”.
I like, “All the best,”.
If I know the recipient a bit I use:
Electronically Yours,
Jorel