Last year, Bethesda released their classic Elder Scrolls titles for free. These two gems are much like their predecessors but with a little more freedom and a bigger scale to explore. Daggerfall is one of the biggest worlds to explore in gaming, even today.
If you’re not running on a system that supports DOS, you’ll want to use DOSBox (try a Frontend if you don’t like reading). This DOS emulator will allow you to play any classic PC game. If you’re on a Mac, I’d recommend Boxer since it’s even easier to use.