Im looking for a new soundcard

but i dont know the first thing about soundcards just need some sense of direction

Price range: $100-$200
Here are my specs

Processor: Intel Core 2 Quad Q6600 2.4GHz (1066MHz FSB) (8MB Cache)
Motherboard: nVidia 680i Core 2 Quad (By: eVGA) (nForce 680i SLI) (A1 Revision)
Memory: 2GB DDR2 Corsair at 1066MHz Dominator (Dual Channel)
Hard Drive 1: 500GB (Western Digital / Seagate) (16MB Cache) (7200 RPM) (SATA)
Optical Drive 1: DVD±R/RW/CD-R/RW (DVD Writer 20x / CD-Writer 48x)
Video Card: nVidia GeForce 8800GTX 768MB (By: eVGA / Asus) (PCI-Express)
Sound Card: Motherboard Multi-Channel High Definition Audio (7.1 Channel)
Windows OS: Microsoft Windows Vista Home Premium

Thanks ahead of time