I see what you mean, that's what I usually call "crossroads music" (and is usually called "fusion [insert genre here]"). Music where more than one thread of influence can be heard. Amongst other discoveries, lately I've been listening to the Diablo Swing Orchestra (they're free on Jamendo) - they mix gypsy, swing, metal, opera, and others.

You might want to lend an ear to Mike Patton's projects as he is known for his unconventional style (Mr Bungle, especially). Also, a lot of "progressive" music from any main genre usually is open and mixes various styles. Take a look at Archive, Jethro Tull or Ayreon, maybe. The good point with progressive is there are a TON of concept albums, with stories etc., which add to the musical experience and contribute to keep you hooked up from start to finish.

Maybe I'll be back later for further discussion, I'll have to go for now. Tell me what you thought of the ones I gave you already.