Best headphones under $200 used?

As another headphone newbie who just got his first set of cans, I found head-fi.org to be an essential site for getting information. If you're set on closed 'phones for their isolation abilities, choices are more limited because top choices seem to be semi-open or open back designs. I'd investigate reviews of the Denon ah-d2000 & Shure srh940. The Shures may not have the audiophile certified panache of brands like Sennheiser, Beyerdynamic, & Denon, but I think they have a very good sounding product line at their respective price points. Bottom line is we all have different shaped ears and preferences in sound, so it takes some research and trial and error to find what headphones sound good to us.

Photon makes great points. head-fi.org is an excellent resource for headphone information. The guys over there are obsessed. I definitely recommend trying on several different headphones before you buy. If there isn't an audio shop near where you live, Guitar Center carries most of the major brands (AKG, Audio Technica, Beyer Dynamic, Ultrasone, Sennheiser). They don't carry Denon, which is one company that would seem to fit your parameters. Beyer Dynamic also has some models in your price range that would work.

Good luck.

I would highly recommend that once you figure out what you want, you check B&H Photo's web site for pricing. I picked up AKGK702's for next to nothing. They specialize in not only photography but also recording studio gear so they carry a lot of headphones and they move a ton of product so they're pricing is extremely competitive.