I remember playing Joust on an old b/w Mac everytime my family visited some friends during the summers. Joust, and some insanely funny/frustrating game where you controlled a paper plane through a house. The boss of each stage was a cat, and to win you had to guide the paper plane through the open window, to freedom!
Mostly playing Everquest 2 at the moment which due to some cosmic twist is actually good.
Also, Katamari Damashi deserves some mention, even though I don't spend that much time on it.