I'll be using them for everything inlcuding movies, music, gaming you name it. I'm happy to spend up to 3, 4 hundred dollars if I know I'm getting a product worth the money. As for the music, my tastes are broad so I prefer to go for flat and accurate sound, although I am a fan of Sennheiser's which some say can lack treble.
My main issue is these higher-end, professional headphones aren't marketed with games in mind so its unclear which are best for spacial sound. I own a pair of Audio Technica M50xs but they're closed back; the treble can be a little sharp and the spacial positioning isn't all that impressive.