Let's get something out of the way from the get-go. The Audio-Technica ATH-M50 Professional Studio Monitor Headphones are a great pair of headphones for the money -- and great headphones period.
What makes them great?
Well, for starters, they're well-built and have a sturdy design that looks and feels like it will hold up well over time, with a thick single cord that terminates in a heavy-duty, reinforced plug. The thick, padded earcups swivel on two axes, and the headphones fold flat for storage, though it's worth noting that the simple soft case they come with is essentially just a bag.
As their model name indicates, these are monitor headphones and they look and sound every bit like headphones you'd find in a recording studio (and some folks will use them for that purpose). Weighing in at 10.1 ounces, they're not light, but they fit nicely and are comfortable to wear. Naturally, since these are over-the-ear headphones, with a closed-back design, they will make your ears pretty steamy on warmer days.
Although they don't have the active noise-cancellation feature of theor , they do a good job of passively sealing out the sound from the outside world. No, you don't get the same level of noise reduction, but they're a good alternative to the QuietComfort 15 headphones for people who are sensitive to the slight pressure of active noise cancellation -- and they sound better.
While the Audio-Technica ATH-M50 headphones are better suited to indoor, stationary listening (they come with a 1/4-inch adapter for plugging into a home receiver), they work fine on the go, and in size are on par with the aforementioned Monster Beats By Dr. Dre headphones. But the Audio-Technicas, which cost significantly less, are a much better value.