Most memorable, no doubt it was 1989. The greatest football game ever played. I don't even care that the Ti-Cats lost, that game was amazing. It won't just be Rider fans that vote for that one. In fact, I'd like to hear an argument against that game being the best Grey Cup game ever.
Others that deserve mention are the 1996 game played in Hamilton between the Argos and Eskimos and the 1998 game between the Stamps and Ti-Cats. My personal favourite memory is the 1999 rematch between Calgary and Hamilton, but that wasn't a very good game for anyone other than Tiger-Cat fans. But 996, 1998 and 1989 are my top three.