Those size charts never work for me, in part because I'm all arms and legs. I really have to go by what's in the geometry chart and compare those numbers to those of other bikes that I've comfortably ridden.

FWIW, I'm 5'4" and on a small (16") Salsa with a ~57 cm virtual top tube. Sounds ridiculous, I know, but it works for me. http://salsacycles.com/bikes/el_mariachi1/

Indy's post makes a lot of sense.