Beyerdynamic DT 100 - 400 ohm Grey by coolfog09
These are ugly and heavy and the sweaty plastic pads start to disintegrate over time. But for that pain they are effortless to listen to for hours because of the restrained flat sound. I have had Sony Pros that fell apart on my and were horribly uncomfortable. I just got some AKG K141 that immediately sound boomy compared to the Beyerdynamics. I also have some Grado SR60 that are brighter on some frequencies and overall more colorful.
When you hear it on the Beyerdynamics you know what it is going to sound like more or less on anything!
I would hesitate to replace these with anything else.