I have a friend who collects vacuum tube assemblies from old computers. They're very impressive on the mantle. Still, of all the vintage computer hardware I've ever seen, my absolute favorite is the CDC Cyber 6600.



This pictures gives the general idea. The swinging aluminum door is better than any bank vault door, in terms of the sheer engineering and craftsmanship that went into it. It's just amazing. Of course, it's hard to beat a Cray 2 for sheer eye candy.



(It's still amusing to consider that the Cray 2 had four processors running aroung 250MHz with 2GB of RAM. NASA Ames' configuration also had a whopping 72GB of disk.)