Any sound would be okay for anything, but a dedicated sound card is very worth it if you do any professional sound editing.
I reccommend the xonar series from Asus. I've had low and high end cards from them and they've been exceptional.
If you're just looking for gaming and occasional video editing, I'd go for the DGX. It runs about $40 and is a great solution if you're on a budget.
If you need something for high quality/audiophile-grade sound, I'd go for the STX. Though they are quite expensive ~$190. I have this in my gaming machine and Its like sex for your ears. Best used with headphones.
However, I'm somewhat of an audiophile. Once you listen to a high end soundcard, you can never go back to onboard or usb.