That's a nice collection. The problem I've always had is that I end up breaking the console and then getting a new one. I broke my PS1 I got a PS2, I broke my PS2 I got a PS2 slim, I broke the slim and got a PS3 etc etc. Because of that I never have an actual build up of consoles as I only ever buy new ones to replace the old ones which I then throw out. As far as which ones to get rid of then I'm not sure. Maybe just the ones you play the least?
I didn't break them as much as they all just stopped working over time. I'm not really sure why, something to do with a laser in the PS2's? The PS1 just stopped reading discs one day etc etc. I don't mean break as in like dropped them and they smashed or anything.