Let me help you narrow it down.

It's saturday night. Only one more day to guess what the smell was. Here's a hint: Just because I said I looked at all the dishes and removed all the excess food into the trash doesn't mean I cleaned everything that I should have. Because I'm disgusting.
So far the people who guessed "old potatoes" and "...water from the A/C catch basin" are the closest.
Tomorrow night I will reveal the winner.