The fun will only ever end if I stop finding new fandoms to cross with.

It's funny, because crossovers are really how I came into fanfic (My first one waaaay the hell back was a Stargate SG1/Voyager crossover). I have heard a lot of people say they never read crossovers... but Inevitable is very good :P. I think if it's a good author, then almost anything can be made to work.