Never seen a Grey Cup win, so the first thing that came to mind was the 2010 comeback game.
As for most memorable loss..2006 semi-final against Toronto. I was absolutely convinced we were going to the Grey Cup at home that year. Up by 10 in the fourth quarter, and Micheal Bishop takes over for Damon Allen and just starts hucking it into the air - and we just let it happen. Kelly Malveaux and Anthony Marlborough literally bounce off each other to allow a touchdown, god damnit.
Still livid at that game.