The website Archive.org has thousands of retro games for old console and computers all free to download and play!

IS THIS LEGAL ? Yes and No. It is (probably) legal for them to host the old-retro games and the roms, but downloading the game may be illegal in your country, check your local laws.

And here are (some of) the links…

Link to M.A.M.E Roms (42 Giga of retro arcade games!!!)

Link to Main page for Mess and Mame

Link to Console Living Room (old console games playable directly in the browser via Mess Emulator)

Link to TOSEC (list with emulators and games)

Link to 525 DOS Games from 1980s

The Internet Archive is a 501(c)(3) non-profit that was founded to build an Internet library. Its purposes include offering permanent access for researchers, historians, scholars, people with disabilities, and the general public to historical collections that exist in digital format. Founded in 1996 and located in San Francisco, the Archive has been receiving data donations from Alexa Internet and others. In late 1999, the organization started to grow to include more well-rounded collections. Now the Internet Archive includes: texts, audio, moving images, and software as well as archived web pages in our collections, and provides specialized services for adaptive reading and information access for the blind and other persons with disabilities.