Well, not sure about the perfect frame but in the case of the pairs I'm currently selling, the issues would be:
PS Morse - impressed by OP/PS quality, even post Luxxotica, so took a chance on trying one of their rounder designs. While they don't look too bad on me, I'm not sure they'd get much use if I kept them.
TF 5013 - very similar to a pair of SALT Alec frames I own/wear already.
TF 5084 - too narrow for me.
ByWP/IC Berlin - for metal frames, I'm a fan of...