yeah BG had Romance, and a variety of mods are available to increase that aspect of BG (have a look at the links on my site <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
NWN too has its modules (mostly by non bioware module makers) but yes due to the fact that NWN is very scriptable you can virtually make you characters do anything <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />