I'm relatively new to audio-to-computer interfaces, but I'd highly recommend the
Focusrite Saffire 6 USB for those who'd like a high-quality interface for their PC.
I wound up in a pawn shop on a lark, and happened to walk out with an Audio Technica large-diaphragm condenser mic for $45, as an after-thought for what I actually intended to purchase there. My intent after that was to record my acoustic guitars using Audacity. I found (like probably everyone else) that almost all the good interfaces are firewaire, and meant for Macs. Well, I'm not gonna buy another computer right now, so...
I literally stumbled upon the Focusrite when I was about to settle for an el-cheapo model that seemed like the only PC-usable option in the store. The input jacks are combination XLR-1/4", and I initially tried them out with the AT 3035. The mic'd sound was pretty well accurate, dependent on mic placement and room-sound limitations.
Didn't even think to try it for direct-recording an electric guitar until seeing this thread. Tried the Saffire 6 on the Instrument setting, and the sound came across quite well for a direct-recorded electric. I *think* I can detect a tiny bit of digital noise under the sound, but if there was more than one instrument (or if I used a higher sampling rate), I think no one would notice it in the final product. The mic'd sound came across very clear with no trace of noise that I could tell.
A direct-recorded guitar will always sound different that your guitar and amp, so if you want the ultimate, you'll need to spring for a good mic and work on your skill at getting sounds with the guitar/amp/mic-placement combination.
I haven't used the full features of this interface (no messing with midi, and so far I've used the headphone-out from the computer instead on the onboard monitor mixer), but I'd think it will be hard to beat in a consumer-level interface for PC.