There're a few good abandonware RPGs worth checking out. Bloodnet and Wasteland are pretty good. I've heard great things about Betrayal at Krondor, though I haven't played it yet. Of course, you'll probably need to download a program that emulates an older DOS environment like DOSBox to play them.
There's also
[Nethack]. ASCII graphics aside, the game's continuously updated (for like 20 years now), and it's pretty fun.