I discovered, quite by accident, that McDonald's double cheeseburgers ($2/ea, recently 2 for $3) microwave really well. How well is really well? They are exactly like when you first buy them fresh from the store.
You can find 4 of these little beauties in our cheese drawer. If you happen to want one, put it in the microwave for 30 seconds on each side. And leave it in the wrapper while you do this.