Acorn System 1
Just have to mention my Acorn System 1 from 1979; this was Acorn's first commercial computer. I received it about a year ago from someone who had it 'in a box under my desk somewhere'. The unit needed some TLC, but after a few PCB track repairs, a couple of replacement logic chips and some rework on the LED display ribbon cable it's up and working again - although I have to admit that I don't run it 24/7 and the display is not up to email or surfing the 'net.
You can see a pic of the unit here: http://forum.6502.org/viewtopic.php?f=12&t=3286&start=15
It's sitting on a pile of parts I have ordered so I can make a replica (when I get round to it!)
More info here: https://en.wikipedia.org/wiki/Acorn_System_1