98+

I was watching an old Daily Show and came across this and thought it was worth repeating.

"We share 98.5 percent of our DNA with chimps.
The other 1.5% ? Well, that's why we kill each other."

However, I have to point out that the exact percentage of common DNA is debated, especially when you take introns and 'junk' DNA into account. Oh, and chimps can be pretty mean, cannibalistic little buggers, so there's that as well.