I used to drink the mainstream beers (I still drink Moosehead and Sleeman HB occasionally) but have moved more towards the micro/craft brews as of late. Steamwhistle is good as always but I've been drinking more Muskoka and Beau's as well.
I do like Mill St. from time to time but I feel like I can taste every individual grain in their Organic.
And as mentioned Creemore is awesome. Cameron's is really underrated too.
Upper Canada was my cottage beer this year.
And yes I am aware Upper Canada and Creemore were bought by the Big 3. They still taste better.