If you can find tapes of games, you should try and hunt down most of Ultimate's input: Knight lore, Underwurlde, Atic Atac, Alien8, Sabre Wulf, JetPac... they are all pretty great. WOrld of Spectrum is great for trying out games that you might be interested in as they are mostly playable online.
Chuckie Egg and Manic Miner are awesome platformers. the Hobbit and Terrormolinos are good text adventure games. Commando and Airwolf are good action games. The DIzzy games are apparently great (only played one of them myself).
Sadly some dickhead publishers have denied access to their games on the WoS site so anything by Ultimate or Codemasters and some others don't appear there. So no Dizzy games
You can also download a program to convert the files on WoS to .wav or mp3 files to transfer onto tapes and build your own collection.