Hmm.. interesting and thought provoking...
I had a kidnap/rape fantasy once... but I had only been going out with my (then) boyfriend for about a year when we decided to try it... I got freaked, and refused to talk about it for a week or so... which was my number one mistake...
I've been pretty lucky, in that I've gotten to try out most of my fantasies so far, including:
being "X"d and pushed to my limits with a delightful array of BDSM toys
having 3somes
having 4somes
partaking in an orgy
fisting
watching someone i love push their limits for me
playing with complete strangers at an adult movie theater
posing for adult website
But the one thing I have yet to try, which has been burning at me to do, is to be tied, blindfolded, and gangbanged (only by people we know, with condoms of course) and be totally at their mercy...
I only hope this one happens soon.. hehehe