PC, Wii, and PS3.
I got the Wii because it is, by nature, something that can't be replaced by my rig.
I got the PS3 because it has a variety of interesting exclusives like Valkyria Chronicles, Heavy Rain, Uncharted 2, Super Meat Boy, Infamous, Red Dead Redemption, and other stuff I can't get on my PC.
I don't have a 360 because A) Microsoft engages in some pretty fucking unsavory business practices, B) They don't have many things I can't get in the other three platforms, and C) Xbox Live. It just...sucks.
Oh, and D) Holy shit do these consoles have shitty quality control. I hear about a red ring from my friends, what, once a month? And I've taken one apart once to take a look and it might as well have been put together with glue stick.