Looking For Best Headphones

A suggestion would be to check out some Reviews to gain some insight into impressions, models (differences) and Driver Type.
Darko does many Reviews on Cans, and Headphone Amps / DACs.
darko.audio
A good Amp makes a big difference ... also FYI > IEMs can be very nice
for an exceptional experience.
Listening for yourself if possible is best ( CanJam ).
A DAC with a crossover / blending feature makes a difference as well.
My listening is done with the two types of  Can drivers, Dynamic and Planar both and two amps with one DAC.
The equivalent of two separate systems ...

Best place to learn about headphones is head-fi.com

I think the main thing to figure out is what headphones do not give you fatigue. Then how much to spend to on those non-fatiguing headphones. I hated my prior Senn 600 headphones because of fatigue with my Benchmark DAC3 HGC preamp/DAC.

I now have 2 headphone amps, a $3000 one and a $500 one. For headphone ONLY use the Topping A90 at $500 is highly recommended by me and is very close to the $3K Benchmark HPA4.. It is a neutral sounding amp. It goes great with my $3K Meze Empy, a warmish sounding headphone. I have not heard the $300 Meze 99 Classic but from what I have read on Head-Fi it supposed to be similar in sound to the Empy.

Your choice of amp will also figure in on the fatigue factor. I had a $2K headphone amp that gave me fatigue and it was replaced by the amazing Topping A90 for 1/4 the cost.

Best for what?  Budget?  Sound signtature?  Comfort?  Type of music?  Open back?  Closed back?  No wonder Thor is angry!  No easy answer.

What sound characteristics are most important to you?  What’s your budget?

Best for me. No telling what:s best for you.