I've been a Blue Jays fan since I was a little kid in the 1980s. My dad went to school in Toronto, and I grew up in WNY so we vacationed in Canada every year. Started going to games in 1988 (I actually caught a foul ball at my very first game, Jays v. Twins, I was 10 years old), and have been a huge fan ever since. I was in high school when the Jays won back-to-back WS in `92 and `93, so that's been my only taste of my team winning it all. Both the Bills and Jays were amazing in the early 90s, and have not done very much since then. So it's been a long dry spell for me both in baseball and football, my two favorite sports.
Since my dad was in Toronto back in the NHL's Original Six days, I'm also a Leafs fan by birth, though not really hardcore. The fact that the Leafs haven't done squat since well before I was born helps, so we just won't talk about that.
I was working at Duke when Duke men's basketball won it all back in 2010, so that was kind of fun to be a part of, but not the same since I'm not really a hardcore basketball fan.