The headmaster at my old school allowed us to use his new PET4016 which the schoolboard supplied to him without any instructions. He had no use for it so he let a few of us mess around with it during the lunch break. A couple of the guys had VIC-20s and one had a ZX-81. After checking out both models I asked for a VIC-20 for Xmas along with the C2N cassette unit. I still have memories of the ZX-81 owner desperately fiddling with the volume control on his tape deck to load programs. That horrible keyboard was also enough to put me off. I managed to pick up a second hand "Super Expander" which gave me "Hi-Res graphics", some extra basic commands and 3KB more RAM.
A few years later I was faced with either upgrading to a C64 or a Spectrum. I stuck with Commodore (along with the other VIC users) while our ZX-81 using friend went with the Spectrum. I managed to expand it with Simons Basic, a floppy drive and a MPS801 dot matrix printer (my Spectrum using friend got a thermal printer which used sheets about as wide as toilet paper and was almost unreadable).
I finally snagged a display model C128 from a highstreet store just before I switched to the Amiga. The Amiga killed my interest in 8bit for a long time, but now I've recently bought a PET8032 (with some floppy drives), a C128D and I have the Chameleon64 plugged into a C64C.