How much are you willing to spend? I assume you don't have a dolby headphone device and are playing on PC. You might wanna get one of those soundcards first, I think Xonar has the DG (and others) which is cheap and has Dolby Headphone. What's your budget? Good emphasis on bass and good positional cues, would be the DT990 Pro, and to a lesser extent, the DT770 Pro 80 as a closed alternative.
I have an Asus Xonar DX ordered due to arrive tomorrow or the next day so I have that base covered. Yeah I've seen you saying some good things about the DT990 pro and it might be a viable option depending on how much money I can get together. If I can sell the speakers and the headset I have now I could be spending up to 300 euro on the next set of headphones.