I love to cook large meal portions and then freeze or refridgerate them in seperate containers for reheating later. My favorite containers are called Take Alongs by Rubbermaid. They are perfect for putting in the freezer and fridge since they are stackable and easy to keep together. When I organize my freezer, these are also my favorites. I just leave the lids off and put small wrapped pieces of food in them so they don't get lost.
Take Alongs are also very easy to clean. I would not cook in them, though since they are rubber and you should never microwave rubber. If I have frozen food in them, I just run the bottom of the container under hot water and let it loosen, and then place the frozen portion of food in a microwave safe bowl to cook. I also love the way the lids fit into each other for storage when they are not in use.
If you are like me and like freezing and organizing, you will love Take Alongs by Rubbermaid.