separates or headset?
if separates you could go for a hd518 $70 (neutral) or its upgrade the hd558 $100 (better pads and build quality) or ad500x $80 (bass light for fps gaming).
for a mic you could go with the modmic $40 (attaches to headphones), the cheaper moovmic $25 (like modmic but not as good), a cheaper mic like the blue snowball, c01u, atr2500 or if you had not much money the neewer products arent bad (not as high volume or bassy response but not bad clarity).
if you have crap onboard audio, wanted virtual surround sound but dont have the option or feel the need for an upgrade a xonar dg may be worth thinking about as well. generally onboard is fine unless you notice issues or have notably bad onboard.
a general use gaming...