DigiDesign 001 with Pro Tools LE, It's been good over the years (PCI bus connected). I have a friends 002 as well but haven't got around to using it as home yet, need a firewire card etc. I've used the 002 with his mac though and it's also a good A/D D/A and has higher sample rates available than the 001. Whatever you get (there are lots available) make sure it supports 24 bit samples as that makes much more difference than the sample rate. 48k 24 bit is a good format, you'll need to dither down to CD (crap) quality 44.1k 16 bit. Most DAWs let you dither (AKA throw bits away) with a variety of dither algorithms. Best way (but time consuming) to dither is to go via tape as the tape warms the sound and is analogue, but then you need good tape (like a 1/2" valve studer mastering machine mmmm, I sometimes use my Nakamichi cassette player). Then you re-sample the tape at whatever format you need. For youtube "quality" (now there's an oxymoron) you could get away with the inbuilt audio chips on your PC but that's not great for multi tracking and will have latency issues.
Also from Pro Tools 10 and later you aren't locked into the Digi Design hardware and can use whatever I/O you like. Some of the Yamaha I/Os come with Cuebase, they work ok for 2 in/out.