1. Water - it comes out of the faucet every time.
2. Clean feet.
3. Heat in my house when it's cold outside.
4. Yes, the washing machine - although some, even one of the people posting here, bought them in their host country, and thus missed and valuable opportunity of bending over a large tub of water and relearning to wash your clothes - whites first, then lightly colored, then dark colors, Because you use the same water throughout the process.