HD 590

Another vote for HD590pro.

I'll say that my favourite pair of headphones ever were the Sennheiser Game Ones. They were a gaming set, but I'm pretty sure they are the HD590s (plus mic). I could wear those for 10 hours a day, and did so when gaming, until the inner ear broke after many years (twas sad). HIGHLY recommend. But if you want something smaller for on the go or wireless, I've had the Bose QC35 Mk2 since 2018 and and use them every day. I can wear them about 3 hours before my ears get a little sore and sweaty (I have autism and am sensitive for them). The battery is still amazing. I replaced the cups with cheap ones after about 4 years, then those after about 3 with the brand ones, and the new ones are much nicer haha. They also sound amazing. Ultimately no headphones will be "for life" because of the nature of taking things in and out. But this is probably as close as it gets.

Sennheiser’s HD500 series models used

Is this actually true? My DT770s had the plastic parts break from dropping them just once. Meanwhile every 500 or 600 series Sennheiser I've had and dropped repeatedly have been as good as new, still are in fact. However, true, the headband itself is solid, if the adjustment plastic clips broke you can just tape them together or something.

Second this. Got my pair of Sennheiser open-back headphones a while ago now and I’ve never looked for another pair since. It takes a while to get used to it but it’s produces gorgeous sound quality.

Yeah totally agree with that, but the turtle beach was insanely bad. I have Sennheiser open backs and while the bass isn't anything to write home about, it's not a noticeable thing.

I have beats fit pro earbuds, and seinheisers open back headphones for my studio at home