Well, OK, the decision has kind of been made for me. My 360's disc drive only opens half the time, and the other half I have to stick a paperclip or something in there to open it. My Wii is modified, so selling it might be a bit of a gray area that I don't want to step into. And the PS3 is my brother's.
But even if I had perfectly functioning consoles, I wouldn't sell them.