I generally like small to average sizes (6-8), wide feet with short toes and *very* high arches, and either 'Egyptian foot' (long big toe, rest tapered down) or 'Giselle foot' (long big toe with the others more squared off, *similar* to Katy's but no 2nd toe sticking out), and polish is a *must* for me.
As Grik says, I have several dozen in my Top Ten, but here are some all-time favorites: Stacy Ferguson (#1 always), Catherine Zeta-Jones, Stana Katic, Kylie & Dannii Minogue, Stacy Keibler, Cristin Milioti, Gillian Jacobs, Franciely Freduzeski, Joanna JoJo Levesque, Maitland Ward, Megan Fox, Nicole Austin, Xenia Tchoumitcheva.
Give all the 'defects' for my own taste listed, I could almost convince myself to rate Katy 'OK' *but* for whatever reason, her feet, just to look at and not considering the individual factors, are 'aesthetically pleasing' to me. I'm very selective with my five-star ratings, but unlike some users, I'm pretty generous with my four-star ratings, and some users throw around one-star freely; I reserve that for Oprah and others in the 'Wikifeet Hall of Shame' with truly repulsive feet.
@toeking- Not used to having to explain my ratings, but I have 'minority' and particular taste in feet. As far as Katy, she has several things that *bug* me but that many guys here love. She has long, narrow feet, decent but not *high* arches, Morton's toe (a shortened big toe, often called 'long 2nd toe'), foot tattoos, and most disturbing to me is what I have called further down the wall 'long alien toes.' Despite all that, to me they are *nice* feet, well-kept, and they look good in heels that accentuate the arch and 'shorten up' the toes a bit.