This is how to fold the fastest paper airplane I know. It can take a very hard throw and still fly well. I credit the design to Surefire Paper Airplanes
*DISCLAIMER*- I AM IN NO WAY RESPONSIBLE FOR ANY DAMAGE CAUSED BY THIS PAPER AIRPLANE- THROW AT YOUR OWN RISK!
WIthout further ado, here is the Instructable! I will reference mountain and valley folds here, so if you don't know what they are, you can check this