Tera Patrick - absolutely every time!
She was always super hot, but her look over the last few years has been so boner-inducing it's ridiculous!
I jack off over her a worrying amount, and this is personal a favourite gallery:
http://www.porn-star.com/tera_pink/free.html
I will literally go through the whole album, cock in hand, pumping away - specific photo for when I cum? Bottom right - tits looking incredible, with a look on her face that is saying "I know what you're doing you filthy pervert" - and she's right!