it's all about the sound for me, nice topic.
in terms of hearing studio material, i can't afford what i consider the 'ultimate listening experience', but i do have studio monitors (speakers) and subwoofer in a relatively well-designed room for acoustics which i'd like to think gives me more of the same sound that the CD engineers heard when they layed down the tracks, rather than to hear it on a consumer system that intentionally "fattens" up the sound (in the makers' view, anway) but more like ruining what the engineers had in mind. the reference monitors give great detail and clarity and stay true to the sound.
i try to avoid using headphones (no matter how good they are) as much as possible, but that's become hard when you've got badly designed walls and neighbors up, down and to the sides of you.
and i've stopped listening to earphone music when out and about. i overdone that ish!
and as for the source of the sound, that depends on what media i use. it's generally hq MP3s, FLAC or WAV and they're all usually flawless, a nonissue, when you've got the right system and environment.