Dvi-d only has digital video information only and dvi-i has both digital and analog. Since the gpu has dvi-d output and has better video anyway use a dvi-d cable.
Thanks for the advice pal I checked out a few local cable shops and bought a DVI-D to HDMI adapter, I have to say that I really had no idea what I have been missing all these time. The difference b/w D-Sub and this is unexplainable. to be Precise while playing skyrim, I couldn't read the boards in the game world and I really thought It was designed to be so..
But now everything works fine