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

Review of MDR-Z7