You can get Sennheiser HD 600s for $289. No need to spend over $500 for amazing sound.
Gaming headsets usually are tuned in a V shape to emphasize the highs and lows which is great for gaming but not so great for music. Good headphones can be great for gaming though as you can use software to give virtual surround and change the EQ. You'll also need an amp and DAC to the the most out of good headphones. Even the higher end gaming headsets recommend them.
Really depends on budget and primary use.
I'd like to hear those Nighthawks.