From Windows Media Player to iTunes and yes, even the beloved VLC, media players are some of the ugliest and least intuitive software around. Plus, storing scads of songs on your hard drive consumes space lickity-split.
Enter the Spotify web client. This streaming music service grants you full access to more than 20 million songs you can listen to on-demand, and for the low, low price of $0—assuming you're willing to listen to ads, or spend $10/mo. to dump them, as well as unlock higher audio quality options and offline listening. Spotify's Discover, Browse, and Radio features do great jobs of surfacing new music to jam to, as well.
If you already have a deep collection of local music, Google Play Music lets you upload up to 20,000 songs for free, then stream them straight to your browser or mobile devices.