I figured that the Union Bank Building and the Hotel Fort Garry would get the most votes, considering that one is Canada's oldest "skyscraper" and the other is arguably the most ornate and distinctive in the city.
I voted for the Confederation Building, but its more of a sentimental thing, my great-great-grandmother worked in that building shortly after she arrived in Winnipeg in the early-1910's.
Its a shame that the Childs Building (211 Portage) was demolished to make way for 201 Portage, its the only 10+ story from Winnipeg's boom period that was demolished (unless you include the Ogilvie Mill), but it would also be odd if we didn't have that current cluster of high-rises at Portage and Main.
http://www.mhs.mb.ca/docs/sites/mcarthurbuilding.shtml