GameStation is a very respectable chain of stores in the UK which, as one might have guessed from the name, specialise in computer gaming.
With over 100 stores across the land, finding one is not a problem. And you'll want to find one; stepping into one of their shops is akin to entering a slice of gamer heaven. This isn't your average couldn't-care-less store - we're talking a proper place run by actual gamers (The fact that the staff actually know what they're talking about is a pleasant surprise).
All five major formats are represented - PC, the Playstations, GameCube, the XBox and the Game Boy Advance. But the fun doesn't stop there, as virtually every other platform known to man is also supported via trade-ins. One can find both hard- and software for the venerable Dreamcast, N64, SNES, Mega Drive/Genesis, and even obscure systems like the Atari Lynx.
Price-wise, they generally stock new games at the usual RRP, although if one applies for their (free) "Valued Customer Card", a couple of pounds can usually be knocked off most new products. Second-hand goods are usually towards the lower end of the scale, but be warned that the staff are well aware of rarer titles and will price accordingly - a PAL SNES RPG recently sold for over £40, for just the bare cart!
All in all, GameStation is an excellent store. especially for those wanting to pick up the odd game for their retro platform of choice.
02/05/2007 update: Alas, the dream's over: Game have bought Gamestation.