Old-school Winamp. I use Spotify these days, but man it was fun to customise skins and play with the awesome visualisers.

Half-Life 3 would also be nice, but I guess it was never "around" to begin with.

- Load any classic Winamp skin just by dragging it onto the main window. - If a skin specifies some transparent regions in its region.txt, they are respected.

Features - https://twitter.com/captbaritone/status/961274714013319168 Source - https://github.com/captbaritone/webamp