Shure 840s. I feel too many people are recommended this headphone with little thought put into associated components. The 440 is hard enough to sound well without some halfway decent source and amp, plus possibly a small mixer in between in it all to offer some control over it. The 840 is made for a studio, more than most, Few cans in it's price bracket work as well as the 840 on a console,but I would not want to tell someone it is musical. My 440s sound fairly good with the right tubes, EQing, and out to a decent amp, but shred my ears out of a DAP, and most digital EQ on portables is audio-mangling.
I feel the m50s earned their place. The are truly versitile, and tonally accurate when they need to be, Often I find they will reduce soundstaging to preserve tonal accuracy, which is something I quite like about them, as I can use them as a reference, not because they cost me 1000 dollars like some other reference phones, but because I know exactly what to expect, and since they can be driven straight from a DAP. it makes this even more important for me to have such a reference when I am considering a new set of headphones, or component.
AKG K271 MKIIs. These are not little kittens. The originals made in Austria were hard to listen to musically without the right setup, and if the MKIIs are the same phones, just assempled in China, then expect similar results. These should not be beginner headphones/first respectible headphones. Many half the price will smoke them and especially the poor modern k240. I am not sure if I have been able to get my k240S *(mine made in austria still, but suppost to be the same), to sound "good". IT is always a tradeoff... good mids and HF with crappy bass, or tighten up the bass and lose the HF to the 5th dimension or something.
Certain Vintage cans that are always looked back with a rose colored nostalgia, being still in production, perhaps, but there is finally now better in that low price point that do not lose so much detail, although they do have a suprisingly open warm sound, instru ments get lost and the lines blur far too soon, 1000X better than ipod buds, but then again, what aftermerket phones aren't?
Just my inflation-adjusted few cents. (and to be on record: the beats are horribly over-rated, and landis, I too bought a pair of DT770s on somewhat impulse, but with 880/990 pads on them, they get quite a lot of use on my systems... like the m50s, I know what I am going to get, and often when they sound *good* on a setup, I know that stup is tuned well, if they are boom tizzy, it is not the phones' fault after having them for this long, they have a great sound for the dollar, and reveal things other phones just don't quite as well for near their price. They are worth owning.)