1. Championship Manager/Football Manager (all incarnations since Championship Manager 2) - PC - Not so much a computer game as a way of life.
2. Magicland Dizzy - Spectrum 128k (+3 in our household) - The fourth(?) instalment of the wonderful Dizzy series kept Baby Brother and I occupied for hours on end, working as a team to solve puzzles in a world populated by boxing glove-wearing anthropomorphic eggs. We didn't need drugs in the 1990s. We had Codemasters to create outlandish fantasies for us.
3. The Legend of Zelda: Link's Awakening - Gameboy - The First Legend of Zelda game on the Game Boy, the first I played and the one I've enjoyed the most.
4. Goldeneye - N64 - Quite possibly the world's best multiplayer game. Four players rampaging around hydro electric dam as Oddjob, Bond, Jaws and russian soldiers shooting each other has never yet been surpassed.
5. Mario Kart - N64 - The best driving game ever. Beaten only by Goldeneye in the multiplayer stakes. There has never, to my knowledge, been a bad version of Mario Kart.
6. Grand Theft Auto III - PlayStation 2 - Not the original, but definitely the best in my opinion. I never really enjoyed the first two games on the original PlayStation, but GTA3 was, and still is, awesome.
7. Pro Evolution Soccer - PlayStation 2 - As any fool knows, Pro Evolution Soccer kicks FIFA's ass every time.
8. Chucky Egg - Spectrum 48k - Falling into the "simple but effective" category, this Donkey Kong predecessor saw the player manipulate Henhouse Harry through level after level of platforms, collecting eggs and avoiding killer chickens. They don't make them like this any more.
9. Sim City 2000 - PC - My second favourite PC game after the untouchable CM/FM series. I've devoted countless hours to building a whole series of Jockvilles over the years.
10. Sensible Soccer - Gameboy - Only on the Playstation did Sensible Soccer suck, but on the original Gameboy it was the greatest football game by a considerable margin.