I've always liked a reddish colour building. It's one of the reasons that Scotia Plaza is my favourite skyscraper in Canada.
I really like all of them but for me it would be:
1. Suncor
2. Telus Sky
3. The Bow
4. Brookfield (even though it's last, I still really like the building)
I'm glad that I did get to see all of them in person last year when I visited the city.
The picture is big so I'll just use a link:
https://s1128.photobucket.com/user/DWils01/media/Alberta/DSC07749_zpskmyzoouh.jpg.html?sort=3&o=132