I'm a chick but I ended up playing as a Male Shep (felt canon to me). So my mindset when coming to choosing a romance option was one where a girl looks at who to pick out for her brother (or something like that). I never really got that idea where you think of yourself as the character and thus make decisions based off that point of reference.
So yeah, I know like, absolutely kaput about any of the femshep relationship options.
ANYWAY, who I chose was...
Tali.
I honestly had no idea how popular she was, as I've only recently played the Mass Effect games and was previously nearly ignorant about all information/fandoms about it. But I really liked her as a character. Some people seem to claim that players only liked her because she was a "nerd" but I disagree. She herself said that Quarians are a very social people - nerds (or at least those of the stereotype) generally have a really hard time interacting with people. Being good with technology =/= nerd. I thought she was nice, but strong. Her sense of humor was adorable. She held her own, but she wasn't a ***** either (big difference). I'd quite like her as a sister.
I thought Jack was really pretty actually (never thought I'd say that about a bald lady), and she pulled off the tattoos quite well, but her attitude was just way too crazy for my taste. She's a freaking psychopath, man.
I didn't care much for any of the romances in the first ME. Ashley was a ***** (a completely different kind from Jack though... I actually prefer Jack's bitchiness), and Liara was just meh to me (and was it just me or did she turn crazyass manipulative in the second game?).
So yeah, my experience with Bioware romance.