I realize that semi-gloss is more washable, but what I have been told is kinda ugly.

Easy to replace, even washable.

Satin is washable, doesn't highlight imperfections, and doesn't look too shiney.

We use a semi-gloss, washable paint with extra coats around light switches, corners, and other areas likely to get dirty.  

All great insights already here Winn, but if you are able to oversee the painting, there are some ways to help with this often unavoidable turn over expense....For example, this time insist on some high end paint (think specialty paint store or the very best big box stuff); try a pearl or washable finish; I like one color for all the interior of all my units, ideally a white that can hide some imperfections (know and keep the code); this means no color or matching mystery later; then on the next turn over, see if you can't get away with just a wall cleaning; use a damp sponge mop with tsp or a tsp substitute  (and then rinse it with a clean water and a damp sponge mop)..not too much water, just damp..