Paint Shop Pro
Paint Shop Pro is the best image editor since sliced bread, and it's not afraid to tell Photoshop to go to hell. It can convert images from one format to another like it's playing a game. I swear it's faster than my brother's brain on a Saturday morning.
I used Paint Shop Pro to turn my cat into a cartoon and got extra credit.
My friend used Paint Shop Pro to add a mustache to his teacher's face and got suspended.
I converted my math test into a BMP just to annoy my teacher.