I also like collecting computers. At first, when I initially started, I was looking for cheapy machines from 1995-1999. Now that I have lost interest in machines from that time period, I'm more interested in machines from 2000-2006. That's the wonderful thing about some computers. It's a quick fix for cheap.
Anyhow, at my height of collecting computers, I had about 20. I got rid of 4, but I got about 4 others, so now I have 20 again. All but 5 of which are regular PC machines.
Since I got my Power Mac G4, I kind of just came across the other 4. In order, I got my Power Mac G4, my iMac G3 (which is now dead, but I still have it), my Core 2 Duo iMac, my PowerBook G3 and my PowerBook G4.
Sometimes I'm impulsive when it comes to collecting old junker computers. Just recently I bought an HP Compaq dc7600 for $20. I got it because it was $20 and the seller was literally a few doors down. What luck, since I found the listing on Kijiji. I have no use for the computer, but I got it anyways. I was also impulsive when I got my iMac G3 and my Core 2 Duo iMac, amongst other computers.