Hi, recently I have purchased Asus Xonar DG 5.1 dound card. its specially good for headphones. I am searching for really good headphones. My budget is max $120. Can you please suggest which headphone should I go to make full utilize of my sound card to have great music and gaming sound?
In my opinion, Sennheiser makes the best headphones/headsets out there, but they come at a premium.
If I were you, I'd wait a bit and save some more money for the Sennheiser PC 333D. For the price, about 200$ (You could probably get them for 180$) they are excellent. If you're willing to pay even more, then go with the Sennheiser PC 360 (about 280$).
If you really want to stick to your budget, then go with the Sennheiser PC 330.
I've just realized that you bought the Xonar DG (about 20$) and not the DX (80$). Considering that, I'd say go with the PC 330. You probably wouldn't profit from a higher quality headset.
Their HD series is specifically designed for audiophiles. They are also way out of his budget. And anyway, with a Xonar DG the OP probably wouldn't hear the difference between the Sennheiser PC 330 and the Sennheiser HD 800.