I recently built myself an i7 rig, and I was just wondering about getting a dedicated sound card instead of using the onboard.
I use my rig mainly for listening to music while web browsing/working, and some fairly heavy gaming.
^ +1 To the ASUS Xonar DX.
It is heads and shoulders above any of Creative's current offerings.
I would recommend avoiding Creative's products at all costs.
They are overpriced, have sub par audio quality, terrible driver and OS support.
Instead, look towards ASUS' Xonar line, HT|Omega or Auzentech for a quality card.
The ASUS Xonar DX (PCIe) and D1 (PCI) are excellent budget cards and either would suit you fine.