Does the the X-Fi series of sound cards offer very good A/D conversion? If not what card would you reccomend for good analog to digital conversion? I would prefer it be an internal card as opposed to an external device.

This one is very good. I used it a lot, never had any problems. Of course its not "high end" but its very good for home studio usage.

http://www.m-audio.com/products/en_us/Audiophile2496-main.html

Theres this one if you need more quality or have 200$ to spend on this

http://www.m-audio.com/products/en_us/Audiophile192-main.html