My main 2-channel system is a Denon AV Receiver with a burned out video board, two Panasonic speakers I got for 1/10 the original cost and a stack of obsolete audio sources (two tape decks and a minidisc player) next to a M4 Mac Mini with a USB audio out that has coax, optical and analog outs so I have all the bases covered. By far the computer is the most common playback source.
The PC is for me as well - I run a Lenovo ThinkCentre tiny through a Yamaha MD8 MiniDisc multi-track recorder which then goes into my Yamaha 5.1 receiver. The MD8 is used for karaoke, and the receiver uses Dolby ProLogic to make it surround.
For recording MDs I use a Sony MZ-N920 with Web MiniDisc Pro.