Gifcities by Internet Archive
find COOL GIFS! A search engine for gifs archived from geocities.
cobalt by wukko download videos from various websites without being tracked
retrocampus BBS
very cool BBS on a commodore 64 emulator, all integrated in a webpage
it has news, games and even an internet browser
phonetones
it has news, games and even an internet browser
A massive archive with a ton of phone ringtones and soundbanks
Mac System 7.0.1 @ archive.org Works straight away in your browser and has some neat games too.