You are the Engineer!

Some have pointed and laughed at you for having both weak armor and weak firepower. You have pointed and laughed back at them, after introducing them to your fully-loaded sentry gun.
You are the brains behind your team's operation. You usually don't deal with combat directly, but instead help your team out by building various contraptions that make things easier for everyone. Your teleporters can help your teammates effortlessly make their way into the enemy base, and you can set up a dispenser anywhere your team might need health and ammo. Your most powerful tool is a sentry gun that can easily guard key defensive positions, and destroy enemies with bullets, rockets, and an automated aiming system, making you the core of any team's defense.
http://quizilla.teennick.com/quizzes/5548446/which-team-fortress-2-character-are-you