If you've not seen any of these videos, be warned of potential spoilers for the series. And if you haven't seen it, I would recommend watching it! My personal favorite is the G1 storyline. It's still humorous but it's far more serious than most of the others.
This is a compilation of moments that my sister and I quote very frequently.

Footage: Random Transformers Skits, The Next Generation One, Son of Optimus, Optimus Prime Joins Facebook, Is Your Daddy Home?, Revenge of the Fallen Fallen, TNG1 Deleted Scenes, The Absurdly Awesome Finale.