24bits,192000hz is what most built in audio will do and you will need pretty nice head phones or speakers to do that if ears can even hear at that rang.
ASUS Xonar DGX is a perfect choice of gaming and music listening. Even though this a budget sound card its much better than most of the onboard cheap motherboard audio. Xonar DGX has on-board headphone amplifier that can boost audio through headphones.