you get

*inserts *

you get a annoying line under everything you type.

*inserts a creaper*

EDIT: Ninja'd. The machine explodes and respawns.

*inserts a box*

*gets a broken box*

Inserts the CanyonCar driver.

You get a custom car in TM2.

*Inserts the first caveman's toaster*

you get combustible lemons

*inserts a 10p coin*

You get a Stout Shakko.

*Inserts two Reclaimed Metal and a Black Box*

You find out how a mysterious plane crashed.

*inserts nadeo*

Hurray! My thread lives on!
---
You get a Liberty Launcher.

*inserts a fancy hat*

(This post was originally directed at Windows 3.1, but looks like the post above me beat me to it. )

you get a hat monster

*inserts a bullet hell shoot-em up videogame*