I would fuck the shit out of Dolly Parton. Circa 1990 would be ideal but I'd still fuck her even now for a bunch of reasons:
1) Those legendary, massive fucking titties. Been jerking off to those since I was a kid - the chance to play with them, suck on them, fuck them, and watch them bounce during coitus would be too much to pass up. I'd fuck her missionary and then bust a nut all over her nipples and cleavage.
2) Her accent. The thought of her moaning and doing sex talk in that country voice gets me so hard.
3) Her legs - underrated part of her that still looks good.
4) Her age - the fact that she's 60 and so much older than me is actually kind of a turn on (I know, I'm a perv).
5) Novelty/bragging factor - she's a celebrity!
6) Personality - she seems really sweet and genuine, and would probably be a very good lover.
7) I generally prefer more natural-looking girls, but sometimes I just get a sexual craving to jerk it to a girl with that over-the-top plastic barbie look. It's like eating - 90% of the time I eat healthy, natural foods but every once in awhile it's fun to just indulge in some greasy, over-processed fast food. Dolly Parton is like the McDonald's of jerkoff material.