My favorite episode of Charmed is on right now on TNT where Prue is genderflipped. I remember the first time I saw this I'd recorded it and I must have almost worn out the fucking video tape watching it over and over again.
And even after all this time... damn.
This is coming from someone who can barely tolerate Shannen Doherty. I believe this was also my introduction to genderflip (pre-internet days for me). *vbg*