Headphone no cost limit.

Here’s a link to a site that covers headphones.

http://www.innerfidelity.com/frontpage

Click on the "Wall of Fame" link to see what the editor thinks of various headphones.

Best headphone?
Open or closed?
Dynamic, magnetic planar, or electrostatic?
Interface single-ended or balanced?
Power requirements, player type?

There’s a lot of variables to picking a headphone. It is also a growing hifi sector that has been bringing a lot of new technology to market.

Good luck in your search.