If you like JRPGs, Tales of Symphonia and Tales of the Abyss are really good and most of the games in the series have interesting stories. The most recent one, Tales of Zesteria, has a pc version. I don't know if the PC ports for the others are any good though. As for short games, have you tried Stanley parable? It has interesting and quirky stories. If you want weird and short, I recommend Jazzpunk. If you like point and click games, the Deponia series has a decent and funny story.