*Groan*
Well, seeing as I never really use the internet when my friends are around and vice-versa, and we never e-mail eachother, I can't say I've ever been the victim of a rickroll. Now, I have indeed seen the video in question, but only when I knew I was going to a rickroll page (i.e. researching said fad on the YTMND wiki). That, and megamush posted a loop of it, but I'm not sure if it counts unless someone fools you into watching it.
Eh, I'll say once. All those technicalities have gotta average out to something.