Linux	Windows	Macintosh
UI	Text all the way.	Mostly icon-based, witht eh powerful Command Prompt.	Text? Oh, right. Words from a keyboard.
Control	100% control. My computer does EXACTLY what I want it to.	I've got wonderful control. I see everything it's running, and -- crap, it crashed.	Um… I run programs.
Programming	What do you want the program to do? OK, here it is, with 20 bonus features.	I got stuff like VB. Simple, but still considerable.	What? MAKING programs? I thought they grew them on farms in Venezuela!
Images	…I can make a stick guy.	MS Paint and crappy Photoshop rip-offs.	Unlimited ability.
Movies	I write what the movie companies use to make the movies.	I watch them. FOR FREE!	I'll make whatever movie you want.
Games	Write them from scratch in my free time.	GAMING FOREVER!	We've got games! All 5 of them!
Input	Mice are for wimps. Unless you mean the live kind.	The mouse and keyboard create a synergy necessary to achieve Zen Oneness.	I mailed my keyboard to the starving children in Pakistan. I figure they could use it more than me.

I apologize to those who quite like each system. I use Windows, and love it, but I know little about the other systems. I'm mostly just having fun with this.