I am personally in the market for a new over ear headphone for around 100 euros (not very strict about it though) and i am seeking some advice as you guys are very good at that.
Personally i've used a few headphones in the past with most of them around the 40-60 euro mark and all of them on ear because i needed something mobile. Models i have used are:
Sennheiser px100, Koss Porta pro(what a great one that was), AKG 518LE(great sound but not very comfortable) and currently an AKG Q460(good sound albeit of varying quality and not that comfortable)
These days i have a bit more money and as i am about to go on summer holidays which will include lots of travelling I am looking at getting a over ear set that will be quite a bit more comfortable and ideally of course with the best sound i can get for the price. Open is most likely not the best of ideas for me as I will spend a lot of time in a car and other places with some background noise i do not have to hear.
I guess i have to mention what I don't find very comfortable about the AKG's I had was that they both seemed to press a bit too much on my ears which would result in eventually my ears hurting. I assume this will mostly be avoided if I get an over ear headphone. This headphone will also not replace my current AKG as its quite useful when you are on the move for short periods of time.
Music I listen to: Quite varied although predominantly guitar based. From extreme metal to hardcore punk to psychedelic rock. However I listen to classical, jazz and a couple other things from time to time. Although I guess the common denominator is that I tend to listen to "organic" sounding music most of all.
I don't tend to listen to music on high volumes so I doubt a headphone amplifier is required. I will use the headphones in combination with my old ipod video G5.5 (rockboxed ofc i am no heathen!) and my laptop.
Personal preferences sound wise: This is always the hardest part to describe properly. Some people might use the same terms for something different. It seems that I prefer stuff sounding spacey and clear/precise, no need for massive bass but not a fan of very trebly sound either. I usually listen at the lowest volume that makes everything come over properly.(I got my ipod set to ranging from -20 to -30 depending on the environment, sometimes even more quiet when I am somewhere really quiet.)
I prefer to not tinker with EQ's, I usually prefer the neutral setting and as I listen to music with a lot of different production jobs/tones it seems silly to do so to begin with.
Design etc is not really important to me, not nearly as much as comfort at least.
Do i need to tell anything more?
Anyway I have been looking at models online. I doubt i can really test any of these in real life so i just have to trust the reviews.
I've heard good things about the Grado SR80i
The Sony MDR7506 is supposed to be the best there is according to http://thewirecutter.com/reviews/the-best-150-over-ear-headphones/ It also is priced quite well compared to the others is see mentioned
there are also a couple Audio-Technica ATH-M50 models but the new x one is getting a bit on the expensive side for me.
This should be enough information i guess.