I'm a little bit worried about that with my gf. I'm primarily a thinking and discussing sort of person, whereas she's a chatting and funloving sort of person- and this relates to our interests.
She likes pop TV like One Tree Hill, The O.C. (which, admittedly, I watch happily now), EastEnders etc., whereas I like more adult dramas like the Wire, Walking Dead, or Dexter- but I've turned her over to Firefly and she's turned me over to the O.C. It's all good.
Musically she likes things that catch her attention- she barely listens to albums and makes playlists of fun songs. I, on the other hand, make a point of only listening to a band's albums, I like getting to know the music like the back of my hand and getting thoughtful enjoyment from it. But we both overlap- I appreciate a lot more songs and types of music and like dancing more since I've met her, and she's into a few things she'd never try if it wasn't for me.
But games... She doesn't mind them- but I tend to rant about exciting ones, it's really important to me, and it's starting to annoy her. Tbh, over time she's really really starting to hate on it. A few arguments have started from my ranting about stuff she isn't interested in. And as you said, Yant, I'm worried/ fairly certain that we're going to be driven apart sooner or later because of our fundamentally different personlities and interests :/
Man, I got all serious on this shit!