I installed DOSBox on my Raspberry Pi today so I could play one of my favorite childhood games: Ultima Underworld - The Stygian Abyss. You can learn more about this game on Abandonia. If you like what you see, follow this guide to set it up on your RPi and be instantly transported back in time with this 1992 retro classic.
I'm learning how to run IRC on my Raspberry Pi so I can have a distraction in my lab. The setup I've got is pretty spartan, but that's what I was going for on a $35 Linux box running off an 8GB SD card. You can do this too! It's simple and fun. Why not give it a shot?