I grew up in Southend-On-Sea and we had a decent mix of computer shops in the 80s and 90s.
Software Plus - Use to visit this in the late 80s and I remember the big wall of Sega Master System and Amiga games at the time.
Estuary Computers - Bought my first PC RAM upgrade here, two sticks of 32MB EDO RAM to bring my PC to a might 80MB.
Silica Systems - This was based in a big department store called Keddies and had a mix of consoles and PCs, I spent many an hour playing on the Game Boy/Mega Drive/SNES kiosk setups and lusting over the PCs and high powered Amigas.
Games HQ - Now this was where I spent most of my time when it opened in a department store called In Shops, it started off as a fairly small shop with a couple of arcade machines and a bunch of games/consoles for sale but they probably opened at just the right time in the early 90s as they quickly had to expand to new premises 5 or 6 times before their unfortunate but inevitable closure many years later. This was where I'd spend hours playing Mutant Fighter/Street Fighter 2: Turbo/King of Fighters etc on the arcades or playing the latest import console games on the variety of different systems that were all set up and lusting after Neo Geo systems behind the counter and in glass cases.
Some honourable mentions as they're not pure computer shops were Argos which had a Sega Megadrive kiosk where I remember first playing Sonic the Hedgehog and Beatties (again in Keddies) which had a NES kiosk machine which I remember playing Batman on and also one of those Virtuality VR rigs (plus it had a ton of cool models/remote control cars, planes etc). Such a shame that the highstreets just don't have these types of stores anymore, I feel pretty lucky to have lived as a kid through this time.