I mix it up. Sometimes it's "regards", but it's mostly "thanks!" lately. I like to give that informal air right at the end, you know?
Once I've emailed someone twice, it's "cheers," or even "cheers!" if I'm feeling really cheery. Then I start signing my name as "-alistairw" rather than "Alistair". It's hot. People love it.
I don't think signing cheers is bad for you, dude.