You can't go wrong with sennheisers but you may want to look into the various sound signatures out there and consider that as well as price/overall sound. Ie if you're a basshead ultrasones fit you better than a pair of 558s or similar.
In general something analytic/flat like the sony v6 is a one-size fits all but some enjoy more fun phones (casual listening vs studio recording and whatnot). I listen to grado 225is mostly myself because I like the odd sound signature and dont care about flat responses
Something else to consider is open back vs closed back. Open will lead to better soundstage and a more roomy feel at the cost of sound leakage (people around you hearing your music) and no noise cancellation. Closed back eliminates sound leak and helps with noise isolation plus generally more bass, at the cost of soundstage.
Amps and dacs from my knowledge aren't generally worth investing in until you have a bigger budget (eg. $150 headphones > $75 headphones + $75 amp). Hope this helped somewhat.