my first set of "professional" headphones were a set of Sennheiser, i have looked for the model but cannot find it, it's been 15 years. Anyway, they were horrible, mediocre sound, completely flat earcups, hard as concrete, expensive. It put me off sennheiser for life.
i've been using beyer DT100 for a couple years, since it's both what the studio had, and what my mate got for his home recording (i dont like mixing.. or even listening, on headphones).
shocking that his two pairs of DT100 sound completely different; so much for "reference".
now i have a audio technica AD900X in the mail, have great hopes. reviews on head-fi are both consistently high and consistently similar, so i'm hoping on a wide soundscape and a near-reference sound. they were also half of MSRP at £100, while the manufacturer's website puts them at £200+.