best smartphone for music?

the fact that being eligible for a phone upgrade makes me happy is, i'm convinced, final proof of my spiritual degradation. in any event, since subscribing to mog i find myself more prone to using my phone as a player, so i'm looking for input as to which of the latest-and-greatest sound the best through headphones (htc one seems to be optimized for audio, but i don't know if there's really any significant difference between various brands). thanks for weighing in.