Should i get a sound card

Hi i play games, listen to music, and watch movies on my computer and i was wondering if i should get a sound card or just stick with the onboard audio. I have my comp hooked up to my 300watt stereo. will i notice a difference if i get a sound card.

IMO, a sound card usually isn't necessary unless:
-your motherboard doesn't have the connection you require (optical, coax, etc.)
-you have very high end speakers or headphones that require an amp to drive properly
-you have exceptional hearing

I have pretty decent headphones (Sennheiser 485's) and a pair of DIY speakers that I'd put up against ~$300 retail speakers any day of the week. They both sound great to me using on board optical output to a home theater receiver. IMO, the money for a sound card would be better spent on speakers, headphones, amp, etc.

so i will not notice a difference