Cinemassively: How not to make a machinima
Before there was the award-winning The Grind series, there was Oblivious Hardcore. When Macheath wanted to learn how to use Adobe Premiere Pro, he packed every possible transition and effect in, resulting in a cluttered, but funny video. If you check out Oblivious Films, you'll see that this exercise definitely pointed them in the right direction, but this video lives on as a testimony for overindulgence.
[Thanks, Drewbie, for letting me use this as an example!]