Well I kind of want to make this a competition of sorts. This kind of thing might be innapropriate for a Wiki but who cares? Post your longest run and how you died for fun and maybe we might learn something from the deaths.
Here's mine: I died during day 47. I basically commited suicide by attacking some beefalo. Why did I attack beefalo? Because I was done discovering everything and wanted to redo my world in a way that I have more experience and I can be successful and more productive in my new life.