Gerelmx1986 has posted a great review of the MDR-Z7 headphones over on Head-Fi. These are great headphones which compete well with those exceeding $1k. The MDR-Z7 list price is under $700 but you can frequently find them used for around $500. I purchased a refurbished pair from a vendor on Amazon for around $300.
Pros: warm n´smooth Sound quality, soundstage, Build quality, comfortable, balanced capable
Cons: Poor isolation