If you're looking to use the headphone output rather than the speaker outputs, I can highly recommend the AKG K-702. They take some time to burn-in but when they do you are well rewarded with amazing transparency and neutrality. Bass is not as prominent as the Sennheiser 'phones but seems more real and less bloated.
My best advice would be to visit the Head-fi website and get some advice from people as hooked on headphones as most on this site are hooked on hi-fi!:-)
My best advice would be to visit the Head-fi website and get some advice from people as hooked on headphones as most on this site are hooked on hi-fi!:-)