Honestly, I don't know why people keep buying the latest soundblasters and pc sound cards. Well, yes I do, it's marketing.
"Audio recording" cards are cheap in comparison and have MORE fidelity and accuracy that those non-recordist cards do, and creative et al. just jack up the price because people are intimidated by audio setup and terminology. If you can handle tinkering with drivers every so often (for instance, to change the sample rates so you get all the audio fidelity in a game), you can save a ton and end up with some neat features you might even end up using-- like some rca or 1/4" or xlr ins so you could, for instance, digitize your lp collection, use any kind of mic for in-game voice instead of being stuck to an overpriced headset.
What astrallite said is not really accurate (no offense, friend). You can live switch the sample rates for input and output on just about every audio recording card using an in-windows driver config. program. So while, if your card is set to in/out at 44.1kHz, your game audio may sound crappy because your card can't resample, you can simply change the drivers to 48kHz. Just make sure that the card you're looking at supports 48kHz. Most now support all the way up to 96khz, and if you're running your card at default of 96khz, you're card will automatically resample to 48khz anyway.
Most recording cards even feature wdm drivers, which let applications share the drivers so you can run them as your default windows audio output device without any kind of error.
Anyway, I'd recommend getting an audiophile 2496 and some audio adapters from radioshack so you can plug 1/8" phono headphones into one of your pairs of rca outs when you need and leave the other pair for your monitors. The card has 24-bit, 96khz, 5.1 coaxial (all digital) out.
Have fun!