There are lots of options on the market, but if you have a Raspberry Pi lying around, it makes a great and very cheap solution!
Apple’s Airplay goes over wifi and gives much higher-quality audio, but you’ll need some way to get that signal to your receiver or amplifier. Bluetooth is an option, but the sound quality is ok at best.
If you want to use real speakers, you either run an audio cable to your stereo (tripping hazard, low-quality sound) or drag out an audio interface ($$, lots of cables). If you’re like me, you have tons of music on your computer but usually end up listening to it on headphones.
