Sure PegLeg, I'm the same way: I want things to sound great too! Okay, here's the deal with the Dolby Digital Live; forgive me if I cover stuff you already know.
So, video games on PCs output digital sound to whatever sound hardware is on your PC. The sound card then translates the digital to analog voltages and outputs these to some sort of amplifier (an A/V receiver or an amp built into the speakers themselves), which then outputs it to the speakers. To hear surround sound from your PC, you need a wire for every pair of channels, so for 5.1 sound, 3 wires.
The other way to output from your computer is digital. In this case, the digital sound from the game goes out of the sound card still in a digital format and doesn't get translated into analog until it gets to an A/V receiver (so you need an A/V receiver to output digital sound from a computer). When outputting digital, it's just a single wire from the computer to the receiver (this wire will be either fiber optic or coax, and the output on the sound card will probably be labeled "S/PDIF"). So the digital sound going across this wire has to be encoded in a way that the receiver will understand. If you just want to output stereo, there's no problem, but if you want to output surround sound, the digital output needs to be encoded in a proprietary format from a company like Dolby or DTS. To do this encoding, however, the maker of a sound card needs a license from Dolby. And because of this license, the games themselves (at least on PC) don't output in dolby format and neither do most sound cards. This means if you try to play your game via a digital output from most sound cards, you will not get 5.1. You'll get stereo (or maybe three channel? Not sure). Note this isn't a problem for movies because their surround sound track is encoded in one of these proprietary formats.
The only way to actually get surround sound via a digital output from a computer is to buy a sound card that supports taking surround sound output from a video game and encoding it in one of these proprietary formats. There aren't many cards that do this that I'm aware of. And I'm not aware of any on-motherboard sound devices that do this (though I've certainly not looked hard for such a mobo). The card I found that did this has something called Dolby DIgital Live, which is the name of the encoder that takes the digital surround sound output from the game and encodes it as Dolby digital, which the receiver will understand. The card is the Createive Labs Soundblaster Recon3D PCIe). With this card, you can use a digital sound output from your computer and still get surround sound from video games.
So, to summarize, if you're outputting analog sound, either directly to speakers with a build in amp or to an A/V receiver, any sound card you find will allow you to output surround sound from video games as long as the card has enough outputs. If you want to output digitally to an A/V receiver (no built-in speaker amps have the ability to take digital input as far as I'm aware) and you want surround sound from video games (again, movies will work fine), you need a sound card that has Dolby Digital Live or something similar.
So the only question is is there are reason to want digital output over analog. Digital is billed as "better" than analog, but just like everyone said for the balanced vs unbalanced thing, it's unlikely you'll hear much of a difference in sound quality between digital and analog. The exception may be if you have some sort of interference in your system or the area that is introducing noise into the analog voltage. Of course, this doesn't stop me from always using digital sound outputs whenever possible - I doubt I need it, but I do it anyway
One thing digital
does give you is fewer wires. You can output surround sound with a single wire when going digital, and it's always nice to reduce wire clutter. In short, if you want less wire clutter, and the "best" sound possible, you may want to consider digital output. Remember that to do digital sound, you'll need an A/V receiver, too.
So there ya have it. Merry xmas to you too!