1. Oscillating fans- seriously if you don't have A/C *raises hand* or don't want to run the A/C, oscillating fans to the rescue.
2. Paper Towels- good for spills, good for napkins, good for just about anything. Like the Queen in chess, and #3, they are so multidimensional, and the best friend of stressed out mothers and lazy single guys everywhere.
3. The "F" Word and it's variations- adjective, noun, verb, it can fit whatever part of speech you want, can be used for so many different purposes, and I mean come on, nothing makes your point better than saying "FUCK YOU" to somebody.
4. Water- Whether you want to go swimming, take a shower, wash your hands, drink some, cure a hangover, water your garden, or cool yourself off, water is ALWAYS there for you. It truly is your best friend.
5. Traffic Lights: Laugh all you want, but try and imagine a world without them.