HD 599

It depends on the use case, for music I would advise the Sennheiser 599, not wireless though.

Sennheiser HD598. I think I got them on offer for around £150 a good 15 years ago. They opened my eyes (ears) to how headphones could offer greater fidelity than HiFi speakers at a much much cheaper price point. I've since upgraded to the 6XX which is a clear step up for music even if not quite as comfortable. Seeing the 599SE on Amazon for £99 today makes me happy that a lot of people are going to be experiencing that same feeling for the first time.

Sennheiser hd 560s or 599 etc with mod mic. 6 years ago I bought best wireless gaming headset, returned after 1week and got the hd 599. Newer looked back or wanted to upgrade. You can actually replace the stock cable to one with mic.

HD 599 hands down

I have some Beyer DT990s i need to fix. My cat chewed the cable in half and so theyve been sitting in a box waiting for me to creck em open and replace the cable. In the meantime ive been using the HD599 from Sennheiser and they have also been great. 

I don't know about the blackshark but I can tell you my experience switching from cloud alpha to 560s. At first the 560s seem to have a lot less bass because of the neutral tuning and open instead of closed back build. The bass punchiness is missing. The sound profile is bright, similar to cloud alpha so I enjoyed the sound from the beginning. It was just perfect, no eq needed  The detail retrieval of the 560s, imaging and soundstage were much better. After using them for about 2 weeks they seem to have more bass. The brain tunes in to the new sound. But I still loved the alphas so after a year of 560s I bought a new pair of alphas (I gave the old one away). But... they did not sound as I remembered :)) Bass was muddy, details were missing, treble was further away. You don't notice so much the upgrade as you notice the downgrade after using the 560s for a while. The 560s are excellent headphones. They have superior soundstage, great detail, great imaging, you hear everything from footsteps to whispers. They are audiophile headphones. People refer to them as mid range probably because they have mid range build quality. But for sound I think they can be considered high end. They can trade blows with the hd600 which are high end. 560s has a wider soundstage and an extended bass response.  Music sounds very good. Voices like Enya, or ballades from Roxette sound divine. I really tried to find a difference between 560s and 600 but apart from soundstage they sounded identically. Same voice, same tonality, same dynamics etc. The velour earpads and open back don't cause much heating. The earpads are bigger than usual, they are lighter than most headphones and are really comfortable. They run just fine on a good motherboard audio or a good usb dongle. No separate dac/amp needed. Beside them getting louder you won't notice a quality or sound difference. I also tested hd599, hd600, meze 99, meze 105aer, beyerdynamics dt770, ananda nano and some I can't remember. In the end the 560s for me is the best pair. With a little bit of desire to also get the 105aer. The reason I gave up my alphas was that the earpad's fake leather broke down and I could not find original replacements. Any other earpad alters the sound dramatically because of different sizes. But the 560s share the same earpad with many other sennheiser models so replacements should be easier to find. Also velour should be more durable than pleather. So yes, at 120 eur they are a best buy. I don't think you could get anything better. 

I don't have much experience. I have used Sony MDR V6 which sounded ok, and Sennheiser HD599 which sounded a lot nicer but definitely not flat, so you would need to EQ them. They seem to be available for €100. Check as many reviews as you can to find something good in your price range. If you have the option to save up more you will probably get something that you will enjoy more. Might be worth trying to figure out price ranges for different levels of quality. With many things, there are jumps in quality level at various prices, but the difference in quality might not be worth the price. €1000 headphones will probably be amazing, but €200 headphones might also be very good, and they should be much better than €20 headphones.