My first memories are playing on my cousin's MB Vectrex... it was monochrome, but it came with coloured pieces of plastic that you'd clip on the in-built screen to make it less boring
In '84 though my big sister got a Spectrum 48K for her birthday... she liked it but nowhere near as much as I did. I spent half my life playing on that thing and typing code from the back of magazines. From the Horizons tape, through to Horace and the Spiders, Hungry Horace, JSW, Booty, Daley Thompson, California Games, Combat School, Cybernoid 2, Uridium and Firelord.
I also remember going to Makro in Brum with my Dad who was self-employed and used to get supplies from there... they had a NES on display with Mario. I was impressed by Mario, but was blown away when a few years later we went to Makro in Bristol and they had a Master System with Space Harrier.
I had to make do with the Speccy for many years but after working a number of jobs as a teenager I managed to afford a 2nd hand Atari STe. My sister was at university in Portsmouth and her boyfriend had an ST too. He used to lend me his boxes of floppies with the Pompey Pirates disks. So many great games... Kick Off, Sensi Soccer, Microprose Soccer, Midwinter, Stnut Car Racer, Chaos Engine, Blood Money, Lotus Esprit Turbo Challenge, Xenon 2, Rick Dangerous, etc... I loved my STe.
For some reason, though, I swapped the ST for a Megadrive with a mate from college

It was fun but I regretted it and still do. Even though I've got the games on an emulator I miss not having the original STe.
Sold the Megadrive and bought a SNES with Street Fighter II in a collector's edition tin, Super Mario All Stars and Mario Kart. Ended up giving the SNES away to my cousins a few years ago.
When I started at university, I had a 386SX PC with 8MB RAM and an 80MB HDD, running Win 3.1! I played Doom, Sim City, Epic Pinball, Wolfenstein and Championship Manager on it. Was then a PC addict ignoring the consoles until my son got a GBA, and now a DS and a Wii.