I personally am using akg q710 with felt ear pads, the headband was rigid and had bumps that after extended use caused discomfort, so i cut some felt and padded the headband. These are the most comfortable headphones I have ever worn. Back when I was using a headset I had a Razer Megalodon but now I have a dedicated mic and amp/dac for my headphones and am much happier albeit my wallet was quite light that day.
ON TO THE PURPOSE OF THE THREAD.
I would like to accumulate a list of as many velvet padded headphones as possible, or simply headphones that you have been able to wear for 6 hours + with no strain.
Personally I require a headphone that doesn't rest on my earlobes (which causes me extreme discomfort otherwise), so the "over-ear" are my only choice.
Replaceable headphone cable is a massive plus, as is a flexible headband/ a headband with very soft pads.
And yes I do know the inherent "open-ness" to velvet ear pads, and where I would like this as low as possible, I just cannot stand leather ear pads for more than a little while.
I wear my Sony MDR-7506 for very long periods of time... I eventually forget they are even there. They are not velvet padded, but there are aftermarket replacement earpads available. The Sony MDR-7506 does leak a little, but the sound is definitely top of the line as far as I'm concerned. When I need to have the outside completely blocked out I will switch to my JBL-J88... which do not have velvet either, but have huge 50mm drivers and super cushiony padding at the parts that may contact my ears & head. The Sony MDR-7506 has a fixed coiled cord that is probably repairable/replaceable if ruined. The JBL-J88 has a flat cord that can be disconnected by a twist lock fitting for easy repair/replacement/storage. When I'm gaming I just use my Razer Kraken Pro's (which are very comfortable too) even though the sound isn't the greatest they are my go to gamers because I enjoy the added bass sounds. Built into the Krakens is a simple mic that is flexible and retractable that I use for in game communication. The Krakens also have a cord that is 2 pieces which makes it repairable/replaceable/easily storable. Comfort is very relative to each user, so it is a very hard question to answer... I hope my description/advise/suggestions help. Good luck.