Baseball - Blue Jays (and the Expos when they were here). That was geography.
Football - Broncos. Elway was my favourite player growing up, so I cheered for Denver.
Basketball - Lakers. Same as the Broncos -- Magic was my favourite.
Hockey - I used to be a huge Leafs fan, thanks to my grandfather and his entire family growing up as Leaf fans. Losing to the Kings in 1993 was one of my lowest moments as a sports fan. I moved to Ottawa in 1996, but even that wasn't enough for me to completely embrace the Senators...it took Pat Quinn being hired a year later before I turned my back on the Leafs completely in disgust. I hate Pat Quinn.