So your planning on an open headphone around $300-$400? There are quite a few options in that range, including, the DT880, MA900, Fidelio X1, DT990, HE400, ATH AD900X, Q701, K702 Annie, etc.
I have begun to stray away from the open headphone market, since they all really sound fairly similar (very roughly), while closed cans vary exponentially. Well, not really stray away, I'm just very content with only one open headphone.
IME, the M50 is really good, but there are better options around $200, like the ATH WS99, K545 (plan on getting that one), M80, 1R, etc.
Still trying to decide on a Wii u or new headphone though... I'll get the XBOX One or PS4 later, since Super Smash Bros 4 will come out soon!
I've never had anything stolen from me!