i think jim was one of the first people pam ever met who she actually wanted, even if she wasn't fully aware of that until mid-season two, and refused to even acknowledge it until after casino night.

i have a lot of feelings on her and roy, but i think roy persued her and pam just...let him do so, basically. she did love him, but he didn't really get her or understand her, and tended to miss the point of a lot of things she tried to say, but he was very much a safe option, so she stuck with him.

what she likes in jim is that he understands her in a way that roy never did. their senses of humor match up almost identically, and they're just on the same wavelength in most situations. pam never has to play catch up with him and try to explain herself, because he usually just understands her, and that was something that she was attracted to before she even realized it.

also, that jim halpert is easy on the eyes.