I know this is old news but I was surprised at how many people don't know about emulators and roms that allow you to play just about all of your old favorite Nes, Snes, Saga, Game Boy, and PlayStation games on your computer and the good part is that your allowed to download any game that you already own.
All of these are free and there are many sites on the Internet that try to make you jump through hoops and even install third party software to allow you to down the games, please don't fall for such sites use the ones from the links below to download your emulators and roms (games).
I only use about three sites and have never had any issues with them, I made another post about this sometime back and even added some videos but this one is just a refresher/reminder so I'm not going to waste your time with anymore useless stuff.
Where to get your emulators...
- Emulator-Zone | this is hands down the best place to find the best emulators so check it out.
Where to get your games (roms)....
- Dope Roms | Not a bad site, has a few too many screens to go through just to download the game but the downloads are clean and in the correct format, unlike some sites that have you download a exe file.