For the full list of resources (including software), look at the pinned posts on my blog.
Legal Streaming:
Popflix: Ad-free, Only 5 Movies a Month on Free Plan
Just Watch: Meta Search Engine for Legal Streaming (warning: doesn't always show the free streaming services anymore)
LibriVox: Public Domain Audiobooks (youtube)
Plex TV: Media Center/Server, Meta Search Engine for Legal Streaming
Hoopla: Ad-free, Supported by Library Card
Soma FM: Ad-free Radio, Supported by Donations
Kanopy: Ad-free, Supported by Library Card
Retrocrush: Retro Anime
Asian Crush: East Asian TV & Movies
Bandcamp: Music Website, Ad-free (Free Streaming But Paid for by Downloads, CDs/Records, & Merch)
Tubi TV
Pluto TV
The Roku Channel
Public Domain Movies: Ad-free
Midnight Pulp
Cineverse
Redbox
Crackle
Cultpix
ERTFlix
RadioSide Internet Radio
Free Music Archive: Ad-free, Supported by Donations
Funkwhale: Ad-free, Fediverse Music Streaming Service
Last FM
Radio Garden: International Radio
Poolsuite: A Retro Beach Themed Radio Website
SOMA FM: Commercial-free radio
Accuradio
Jazz Radio
Icecast Radio Directory: Radio Directory for the FOSS protocol, Icecast
KVMR: Community radio
Epic Rock Radio
Libre FM
VIMM: Emulator & Archive for Old Games
Bootleg Sites:
1337x
1337x: List of Mirrors
Anna's Archive: Ebooks
Audiobookbay
Audiobooksbee
EZTV
iDope: Torrent Search Engine
Library Genesis: List of Mirrors
Nyaa.Si: Anime Site
Pirate Bay
RockBox
RuTracker
Sci-Hub: List of Mirrors
Torrent Funk
YTS: Movie Torrents
TV Simulators & Live TV:
Bummer(dot)com's Music Videos: Select a music video
Caith/S4t1nr1bb0nz's TV Guide: Select a program from the TV Guide
Channel 99: Download a TV stream to play in VLC Media Player
Daximus' 90s Page: Flip through old 90s youtube clips with a remote
EXP TV
Frutiger Aero Archive's CRT TV Simulators: Upload video files, embed video/website links (works with any site that allows embedding or iframes even a few streaming services), or simply watch the default playlist
My Retro TVs: Choose a decade of television and watch youtube clips
Olliveen's TV Room: Select a youtube playlist/video including ones for full episodes of TV shows
Poki TV: Select a show from the TV Guide and watch the theme song
Robophobia's Videos: Select a VHS & drag it into the VHS player
Tofokyo's Homepage: Just press the play button & it'll show a livestream
Toonami Aftermath: Old toonami cartoons & anime
TV Garden: Select a TV station from around the world
You can also use the live TV function on most free streaming services.
Not Free But Worth Mentioning:
Robert's Anime Corner Store: A Site for Anime DVDs & Mangas
Sunny's Video: A Site for Horror/Comedy/Scifi DVDs & Blu-rays