I'm using a SoundBlaster Audigy SE. I honestly don't know a whole lot about audio hardware, so here are the specs from the Creative site:
24-bit Analog-to-Digital conversion of analog inputs at 96kHz sample rate
24-bit Digital-to-Analog conversion of digital sources at 96kHz to analog 7.1 speaker output
16-bit and 24-bit recording with sampling rates of 8, 11.025, 16, 22.05, 24, 32, 44.1, 48 and 96kHz
SPDIF1 output up to 24-bit resolution at selectable sampling rate of 44.1, 48 or 96kHz
64-Voice polyphony and multi-timbral capability
128 GM & GS compatible instruments and 10 drum kits
2MB or 4MB GM SoundFont Bank2 included
On-Board Connectors
Signal-to-Noise Ratio (A-Weighted) = 100 dB (2V)
Frequency Response at -3 dBr = <10 Hz to 40 kHz