The large Audio Technicas are fantastic for vocals and acoustics and also highly regarded for gaming. The AD700 and A700 are the entry line (open and closed respectively), the AD2000 is generally considered king of the hill for female vocals (you can find it for around $400 used) in the open side, and the W1000 for the closed side can be found within your budget as well.
Thanks for the reply! The ATH A700 looks very nice. Anything between the entry level A700's and AD2000? I wouldn't want to buy used.