comfy headphones

[2xShi_2xSon]

In the 100-150$ range the most comfortable headphones for long long sessions ...

[Ashley]

HD 558/518s are comfortable.

[TheKDub]

Well I'm getting my Audio Technica ATH m20xs tomorrow, though they are a bit under $100 (Cost about $50, I'm sure the m40x or m50x is about the same or better comfort wise) I could let you know how comfortable they are.

[NannerBeans]

Shure 440 with 840 pads is more comfortable than the Audiotechnica line if you're looking for closed. AKG K612 comes to mind for open but that might be just over your budget. You could also wait for the Beyerdynamic DT line to come down in price again. They're currently at $200 but are sometimes as low as $150. 

[Trimen1000]

I've worn the Sennheiser 558s for 6+ hours with no problem. So they are very comfortable for me, and I have a huge head. If you know people with different headphones try theirs on. Lastly try just going to a store and wearing different ones to try and get a feeling for them.

[mister_s]

I recommend the HD 518 for an affordable solution

[nils4pils]

Razer kraken pro or 7.1

[TheKDub]

Got my Audio Technica ATH-m20xs today, Very comfortable from what I've tested so far (About 5 minutes of use, will keep updated), and the quality of the audio is amazing.