Our first rig was a ZX Spectrum. Later on dad bought a 286 with 256 color vga and a 40mb harddrive. It was an amazing improvement.
My own first rig was a 386 computer i assembled myself. I was very scared at assembling it, but it saved me about a 4th of the cost.
I quickly found out i could do more with computers and electronic parts than most people could. Still to this day i love to tinker with parts and computers that people have thrown away or gave to me.
I've made a multimedia gaming device out of a ten year old Navman navigational system. (Windows 5 CE can do a lot if you tweak it a little).
Last week i made an VMWare ESX 5i server out of an old HP desktop computer. It isn't fast, but it was totally free.