Belladonna, one of the most famous porn stars, known for advocating fetishes into mainstream porn. Has done a lot of foot fetish porn, as well as many other things. If you're interested, check out her party of feet, foot soldiers, odd jobs DVDs. If you're not into porn, she has some excellent foot videos on youtube!
Again, I must make the distinction (for me, at least) between "beautiful" feet and "sexy" feet. I think that there are prettier feet than hers but hers a very sexy - as is she. Combine this with her genuine passion for feet and she's unbeatable.