Some thoughts:
A lot of these responses seem to be centered around ****y/funny and evasive action. My thought is that this only works if you have generated some sort of social proof/ pre-selection. In other words, a playful response works best if she thinks you've slept with women before.
However, if she thinks you're inexperienced, these answers will seem like you're hiding something. Basically, these answers work in accordance with pre-selection, IMO.
And although you shouldn't tell your actual number unless you're in a serious relationship (read: marriage), you shouldn't be ashamed of it either. The number of women you sleep with is not necessarily correlated to your worth or value to the opposite sex. I know some guys who are complete tools who have slept with more women than me, but they do things like: (1)sleep with girls who are marginally attractive, at best, (2) use getting drunk as an excuse for ****ing ugly girls, (3) lie to girls, telling them they love them in an attempt to **** them, (4) take advantage of drunk girls, etc. You get the picture. I have better game than these guys, yet I have standards and morals.
I also know a guy who has only slept with one girl, but he has been in a serious relationship with her for 3 years and she is smoking hot. He is also a really cool guy, who could assuredly get other girls were he single. I have more respect for him than for the guys who have ****ed more girls than I have.
Also, if you're a virgin: Fake it till you make it. There is nothing wrong with not having had sex before. Just learn the skills necessary, apply them, and you will get laid, sooner or later. Don't be ashamed of it, just work on it.