My wife, who is one of the most organised people I know, is nevertheless what I would term a ‘fridge anarchist’. I like order, she puts anything anywhere. Lifehacker agrees with my way of doing things.

Store snacks, leftovers, and other items that get consumed quickly (that could also go bad quickly) on the top shelf. The middle shelves are for dairy, cheeses, cooked meats, and leftovers. The midsection tends to be on the cooler end, so store your milk and eggs here, and they’ll keep longer. If your milk doesn’t fit in the middle section, you can easily rearrange the shelving to accommodate your needs. Items that contain bacteria need to be kept separate to avoid cross-contamination—store these items on the last shelf. The bottom shelf is perfect for raw meat and fish, and should be wrapped or stored in sealed containers. The drawers are for your fruits and vegetables. (Though they can be too moist for mushrooms.)
Source: Organize Your Fridge Like You're a Goddamned Adult | Lifehacker