The two obvious top choices are Blue Mountain in Collingwood (apprx. 2 hours from Toronto) and Mount St. Louis Moonstone, just North of Barrie (apprx. 1 hour and change) Blue always has a consistent park, hosting the big competitions in Ontario, and has a lot of selection of runs. MSLM keeps uping its game every year and has a very solid park, both with a lot of NSers.
If you are looking for something a little closer to Toronto, there`s always Dagmar and Lakeridge (North of Whitby/Ajax) just east of Toronto, which are both about 30-45min from Toronto. Both have chill atmosphere and have small to medium features in the park, but don't go for just skiing runs, waste of time.
As for the other places in Toronto, I'm not to sure about them, they probably aren't worth your time if you are wanting to ride park.
Hope that helps.