Well, looks are looks. Personal preference etc. Girls I'd want to be intimate with should be someone I connect very well with, the conversations flow with a fun tone etc. If we are in a relationship, then, well I'd like her to act well, as in, not be flaky, arguing over nothing, going from hot to cold etc. All these are red flags that tell me to get out. When it comes to just straight up personality, she should be a fun, upbeat and happy person. Not too much emotional baggage.
When I am friends with a girl, she could be a hell to be in a relationship for all I care, as long as she is worth something to me as a friend, i.e good conversations, I can talk to her about things I can't with others etc.
It really all boils down to attraction, a very abstract thing. Its hard to explain, but looks and personal preference is certainly a big part of it.