Why is it that people assume a romance sub plot is something only girls are into?
I mean, I could list a number of games that I liked that had a very deep relationship you could get into with the NPCs, but I'm a boy so what do I know right?
Ok ignoring the sexism in your post there

P), you have got to play the Persona series. I played 3 and 4, you had to get to be friends with the people you where trying to date, had to get to know them, build a relationship take them places, ect. Plus, the things you say to them matter. You could say the wrong thing and make them mad at you, that could lead to a break up or them not talking to you, then you had to make it up to them. You had to be careful to keep promises, had to balance seeing them with everything else going on. Probably the deepest system for this of any game ever.
Your right about Bioware romances being largely "talk to npc untill sex scene". Which one of the 2 cut scenes you get to watch is what most choices in their games boil down to.