I like the miniature stereo receivers from mini/executive/bookshelf stereo systems made by Yamaha, Denon and Onkyo. If you pair them with a good pair of bookshelf speakers and possibly a sub, you can build a stereo that's small and looks nice, and sounds vastly better than iPod docks and such.
They sometimes have a built-in CD deck, sometimes separate. They're usually sold with low/medium quality speakers so you either want to look for the electronics on the used market, or buy the system new and ditch the included speakers.
They're low powered (usually 15-40 wpc) but hearing being logarithmic, it's plenty if you're playing them at moderate (even moderately loud) volume.
I generally like the Yamaha Pianocraft ones, but there's one Denon ADV-M51 that I like because it has the rare and elusive legit subwoofer crossover with highpass and lowpass filters.
Edited to add: If you want to play music off your computer or streaming, rather than paying for advanced "network" products, I would just get a $30 Bluetooth receiver, plug it into the aux jack, and play the music from your phone or computer.