I recently bought a Tiamat 2.2, questionable purchase (from the reviews I've read after buying) but I was in a rush and didn't really look into all that much. Anyway, as the title says, I'm looking a decent sound card under $100.
The new Creative line looks pretty good.
You also have Xonar DX.
Intel i5-3570K @ 4.7GHz | MSI Z77 Mpower | Noctua NH-D14 | Corsair Vengeance LP White 1.35V 8GB 1600MHz
Gigabyte GTX 670 OC Windforce 3X @ 1372/7604MHz | Corsair Force GT 120GB | Silverstone Fortress FT02 | Corsair VX450