I've got one dell latitude laptop that is about 4 years old and about time for replacing. It's mainly my wife's pc, so I can't do much experimenting with it.
Also a dell opti-something that I found in a dumpster. It was loaded with about 120 viruses, so I wiped it out when I got it home and installed linux. It's a happy computer now.
Also got a dell GX110 that my dad found in a house he cleaned up. Not much to it, just a 700MHz cpu and a little bit of ram. And of course linux now.
Last in line is a sony vaio that my pastor didn't want anymore. It's old too. I don't even know what the cpu rating is on it. If it's even got one. It had windows 98 on it, but now it's got nothing on it. Not even linux. Linux didn't even like it!
At work, it's another story. Both my computers have over 3GHz processors (one is dual core) and at least 2gb ram and probably close to a tb of hdd space each.