Try a few things out, listen to other people’s setups, work out what matters to you. I easily get caught up in specs and numbers, and end up aiming at a sort of “ultimate” end-point. The rig that I’ve enjoyed listening to most, of late, is an 80s Marantz amp running a pair of big Celestion speakers (like really big, Ditton 33’s or 44’s). I’ve heard cleaner, more detailed sound, but this setup sounded great, very warm, plenty detailed for me, and not in any way fatiguing. I guess what I’m saying is that sometimes “technically best” isn’t the same as most enjoyable, or best for your use-case

Hot take, don’t spend more than you earn.

For my closed headphones, which are most critical for me: something I can save up for.

For the living room: amp + speakers should be affordable. My living room is not audiophile proof and will never be so getting the best gear is just lost money.

In-ears: i take these everywhere for calls or some music in transport. So they should be kinda dispensible, so if an audiophile tells me "this is good value for a low price" I'll take it.

I did not include numbers on purpose, right now I have a good income so €50 is "cheap" but in other times in my life that would have been a big purchase that I would rather spend on things like food or a warm coat :-)

It is a luxury thing after all.