Mmm....F1GP, SWOS, Poing 4 (gazillions of levels, but the lure of the high score is always there), FaYoh 2 (I WILL complete it someday! I WILL!!!!), Oh No! More Lemmings (er, ditto. 95% complete), Bill's Tomato Game (Argh! 99% complete!), Ruff 'N' tumble (difficulty level is pitched absolutely perfectly).
Not to mention Civilisation and Colonisation! come on, on with the lootings and the pillagings!