So, I'm a big rpg fan, and I just found this game online.
Maple Story
It's completely free, and rather simple. A 2d sidescrolling rpg (as odd as that might be) it's very similar to games like Mario and Sonic. However, it gives you rpg goodies, like different classes, abilities, quests, etc. It's a fun, free, easy game.
Uhm yeah, the downloads on the main page. Look for it, you'll find it.
Have fun!