Hmmm.... Don't think I've ever noticed this thread. It's sorta' buried, you know?
Anyway, I'll keep it going here...
When I got started in the PC-as-music-server game, I was using an old Dell desktop as my digital source, but I'm currently-using my Compaq Presario laptop along with an HRT MSII external DAC (It sends/receives data via asynchronous-usb... I'm VERY-happy with it). I then run a pair of AUVIO rca cables. AUVIO is Radio Shack's high-performance audio line. Really-nice cables with impressive build-quality. I like them better than the Monster rca's, I've used. I'm a musician, so I've seen my share of rca's and 1/4" cables over the years, and the AUVIO's are a good "get it and forget it" cable for people who don't want to pay $120/ft for some overpriced designer-cable.
The AUVIO rca's run out to the "AWKS"-in on my Sansui 2000x receiver (From 1972... 39wpc). From there, I run Radio Shack 14ga speaker wire out to a pair of Wharfedale W60E's (From the early '70's as well... Intro'd in '71... 3-way acoustic-suspension design with a 12.5" woofer, 5" mid-woofer, and a mylar dome tweeter).
For music-storage, I'm currently-using WD My Book Essentials (I have two 1TB models and one newer 2TB model, and I connect them via an external usb hub that connects to my laptop. With the new 2TB drive especially, I unplug it from my laptop when not using it (I heard that it doesn't completely go to sleep when connected to a laptop, and supposedly that puts more wear and tear on the drive... I only plug in what I'm using, and then I unplug it from the external usb hub when I'm finished... I'm also unplugging my DAC from the external usb hub as well... The LED stays on if I merely disconnect the hub cable from the laptop). The external usb hubs take the strain off my laptop's usb hub, plus I get much-better sound with the DAC plugged into the external hub (The DAC performs a lot better if I give my laptop a little help). I use one hub for the DAC and the other hub for the external drives, and I plug the external hub cables into my laptop's usb ports. These extra steps seem to make a big difference with my low-powered laptop, and I get better performance from the DAC.
For playback, I'm currently-using VLC Media Player along with a plug-in called Virtual Audio Cable for bit-perfect playback. Works really-well on my cheap laptop (I was having a hard time getting either WASAPI or ASIO to work properly, but V.A.C. worked fine right off the bat and it's plug-and-play with VLC Media Player).
In my digital music collection, I have all sorts of audiophile stuff... MFSL gold and silver CD's (I like the early silver ones the most), DCC/AF gold CD's, Sony Mastersound gold discs, hi-rez FLAC, test CD's, Japanese black triangle and 2nd-pressing CD's (The AC/DC Japanese 2nd-pressing CD's are great), vinyl-rips (I have a ton of really-great vinyl-ripped stuff taken from 1st-pressings), old-school rap CD's, jazz, classical, plus I've been putting together a movie collection as well (separated into individual genres). I've spent the last 4 years putting this together, and I've been backing it up as I go along (I do physical backups... I don't like the idea of using online servers, especially after seeing what happened to MU and all there customers recently). Your source material is just as important as the source gear IMO.
At the moment, I'm getting surprisingly-good digital sound. The MSII DAC sounds incredibly-analog. It's transparent in the way that it DOESN'T sound digital, and it integrates extremely-well with my vintage setup (especially for a $150 DAC). Now I'm just looking to upgrade things on the computer side (as well as the external hard drive side) and build a desktop computer that can handle the wear and tear of multitasking while simultaneously-surfing the web and all the other basic things people do with computers. It's a lot to ask of an entry-level laptop, so I'd like to put together a custom setup that can handle the job without flinching.