Gamedev resources
VideoGameSprites.net
Free sprites of known videogames available for download.
itch.io
Known in the indie gamedev community, a site where you can share your own projects, download and buy assets, and play indie games.
OpenGameArt.org
As the name says, an open source video game art page.
Videogame Music Downloadsd
Game soundtracks available for download in MP3 format.