Romances can indeed be fun, but so far I only liked one in all games - Aerie in BG2.
I probably would have liked Viconia in BG2, too. From what little I've seen BG2 evil parties are really funny. But I have never figured out how to play BG2 in an evil way that really worked. I really dont want to run around killing random peasants just to keep the reputation low whenever it gets too high, and thats the only way I found to make it work at all.
I already dont like the Bastila romance in Star Wars: Knights of the Old Republic because its merely seven dialogues. How is that even a romance ? Its extremely subdued. Playing evil in KotOR is kind of trivial, just whenever you did something good in the regular game you would do the opposite instead in the evil game. You still get the exact same romance though, and still the exact same girl.