Just my 2cents. I had the Audio Technica M50. They were amazing. Some of the best sounds I have heard. The only issue (as pointed out earlier by someone), they were not the most comfortable ones. DONT get me wrong, I could wear them 5 hours non stop without much issue, but after this they started to get annoying. And yes they were quite heavy as well. Ended up selling them after an year of use.
I recently got Bose AE2 for myself as I always loved the feel and comfort of them! They are not the best sounding ones around - at least not as good as M50, but they are above average for sure. I picked them up on a decent sale. No regrets on the Bose. They are the most comfortable headphones I have ever tried (and I have tried quite a few!). I would go back to Audio Technica M50 if they were more comfortable and a bit lighter..
If you want comfort, use the Bose as your baseline! Their plush leather earcups are super plush.
I also have Logitech Gaming headphones - I have used beats as well (they are ridiculous!!, they look alright yes, but thats about it!). Also tried out Soul by Ludacris - i swear, never buying hip hop artists headphones anymore. Well, 50cent just released star wars headphones - I'd get those.. lol.. Also have used Sennheiser PX200ii and HD260 which were good as well. But Audio Technica are best of the bunch in terms of sound quality.
I would love to try out AKG and Grado. Have always heard good things about them but never sure which one to get. And I cannot justify buying another set of headphones at this stage.
Hope that helps