I like this dad's style.
There's a cruel game on the web that I've loved for years. You have to drag your mouse through a windy maze that gets more and more narrow as you go. Just as you focus more closely on the screen, Linda Blair from the Exorcist pops up on the screen and screams at you as loud as you can imagine. I've scared so many coworkers with this over the years!
Here's an awesome dad who plays this prank on his little boy. The funniest reaction to it I've ever seen.