I to live in manitoba, what is your budget? what size were you looking at?
mud terrain? all terrain?
ive had several of each. right now im riding on Hankook MT's and love them. little sketchy on straight ice, but honestly i love them. amazing in deeper snow, easily useable on packed snow and ice. never used in summer so i cant comment on their mud abilities, but they were rated the top MT by 4wheeler magazine in 2011.
Duratracs are what a lot of people run, theyre great on packed snow and ice, they are a softer tire so they will wear faster.
I ran falken Wildpeaks before the hankooks. they were great in the snow, not so much in deep snow (2' or deeper) they are decent, but need lots of throttle.
decent in mud, but they are an all terrain, so they wont be amazing.
ive used several other tires as well, did you have any you were interested in already?