I was looking for video of a few ZX Spectrum games and I came across this site: 
http://www.zxspectrum.net/
It has a whole bunch of games from the ZX. I played Top Cat for the first time in about 18 years. Brings back memories.
The only real problem with the site is the ingame controls. The controls are all unexplained for the most part and the first few minutes of a game are spent trying to figure them out.