I like aventure/fantasy games too, but I also like Scifi games... it just depends on whatI'm in the mood for really.
If I'm in the mood for Fantasy, I play conqueronline.... and soon when I get STar wars the online game, I'll have a choice for when I'm in the mood for an scifi slant.
I really love morpgs... mainly because I'm a very social person, and I love to be able to play with other players... that way, we can pass the time talking together when we're on one of our quests or such.
Not to mention NPCs (non-playable characters) or some other characters in games that don't talk very much other than to give you choices in quests and such, isn't very intersting to me.... they all often repeat themselves and never say anything new.
at least with an player character, you know they'll be sure to say something new, and not to meiton regonize you if you had been grouping with them for a while