Alice and Kev

Alice and Raph both pointed to this awesome, gripping story of Alice and Kev, an experiment-slash-narrative by a game design student in the UK. She created a homeless father and daughter in The Sims 3, took away all their wealth, and then set about letting them live their lives.

Awesome on so many levels. The depth of story possible in Sims3, the depth of the engine to allow for emergent behaviors, the irrational traits & behaviors that show some of the game's design limitations...

Anyhow, go read it starting here.