If there's romance, it needs to be based more on actions rather than words/conversations.
I would prefer the DA:O system without the gimmicky approval meter over Mass Effect's talk-n-bang romance arcs etc.
Witcher 2 was interesting in that it felt organic but I hated how we are pushed into the whole thing without much choice.
Make sure that the companion is still interesting even when I DON"T romance that particular character.