All all of us in the email world know that the act of ending of an email with the perfect "signature" can break down a human spirit quicker then the time it takes to run to your mirror and shout, "Why do I feel this unnatural social pressure?!"
This obviously does not apply to those who are still unsure about using "The Facebook" and other interweb foolishness.
For those interested however, some basic rules of thumb courtesy of The Hairpin:
The first thing to know is that this sign-off (the closing word or words at the end of your missive) is more properly called a “valediction.” Derived from the Latin vale “goodbye” + dicere “to say,” it’s the opposite of a salutation. Now that you're feeling fancy, we can get down to brass tacks.
When you're feeling aloof: "Regards"
Ending your message with a bare noun like this shows you to be calm, collected, and a little bit bitchy. These regards aren't particularly good. These regards aren't particularly bad. These are just some regards that happen to exist, like a point in mathematical space.
Alternatives: "-[Your name]"
When you're writing to Lord Voldemort: "I beg to remain, Sir, your most humble and obedient servant"
Who are you? Sit down, you're embarrassing me.
When you're feeling rly kewl: "ttyl"
Don't use this.
When the stress of selecting an appropriate valediction gives you shingles: "Sent from my Blackberry"/"Sent from my iPhone"
If you want a way around this whole valedictory business, consider cheating and making “Sent from my [smartphone of your choice]” your default email signature.
Alternatives: This is a chance for you to pretend to have the smartphone of your dreams. Don't be afraid to make something up! "Sent from my Talaria." "Sent from my EnVoyer." "Sent from my iBox."
When you're feeling too cute for words: "Signed, Sealed, Delivered"
Alternatives: None needed. You've reached the pinnacle.