Pfft my tastes are subjective, first i always wanted proper hi end reference sound and closed cans (that sound just like open cans to an extent) because of the bass factor.
About 10-15 headphones got me hooked on better sound, sub bass extension is very important to me, it has to be like a sub bass monster but with proper mids and highs like that with cans that are much less bassy which gives better mids or highs so far the denon d7200 has done that very well for me.
Apart from great subass, it has also has to have rumble slam and impact which the d7200 do very well being the best they can.
Also the headphone has to be fast as possible to give sound delivery as pfft and exactly as pfft not pffst that slower cans have.
so those 10-15 heads were low fi and mid fi cans that costed like £100-400.
Now that i have heard the denon d7200 it is in a completely different league and because of the d7200 i will be looking at other headphones in another league from these as well, like the denon d9200 or fostex th900.
The d7200 will addict me to better sound thus far, if a headphone does not have proper bass rumbling (like with d7200 these headphones vibrate very much with rumble on my head) slam or impact i will forget about it, because bass is a fundamental part of music for me for it to be fun to hear but very realistic at same time, also not just bass but proper mids and highs as possible also the sound signature is verry important to me as well.
So yea the d7200 i have now, i really like every aspect of the sound, but sometime i will get a headphone in another league to these when i can afford heh.
Anyways i will say which exact headphone got me hooked on good sound or sound quality is these headphones, the sound magic hp 151 (good all round sound) , beyerdynamic dt48 (nice mids), ultrasone hfi 580 (bass was nice not quite the sub bass i wanted though or type of bass), also the fostex t50rp is sounds in someway like the dt48 but with the best uncoloured sound that is but the dt 48 is known as a honest uncoloured headphone.
Really i am a bass head, also a uncoloured mid centric fan and a treble head at the same time, so out of my tastes the denon d7200 does very nicely here out of many headphones i have heard.