This site has tons of old games from the 1970s-2000's available for download for free.
Direct links to various emulators as well.
I've seen some people have issues with running the downloads, but if anybody can figure it out (if there even are any issues) you'll be on here.
You can also search by genre, year of release or platform.
Here are a few of the titles that are available for download:
Destroy All Humans! 2
James Bond 007 Agent Under Fire
Golden Eye 007
Medal of Honor (& Rising Sun, Front line)
Pokemon Colosseum
Fable 3
Silent Hill, 2, 3 and 4: The Room
Resident Evil 2
Shinobi Way of The Ninja (2005)
Marvel Vs Capcom 2 New Age of Hero's
NBA Street Vol. 2
Crash Bandicoot: The Wrath of Cortex
& many more.
Enjoy