Oh my goodness. Banff is GORGEOUS. So, so pretty. A nature lover's dream. I traveled there at the end of August, and it was the perfect weather. It wasn't super crowded, I'm guessing since school had already started, so we had a lovely time exploring the different locations with relatively few crowds.
I spent about a week there, and I could have spent a lot longer. Much longer. Didn't have enough time to drive up to Jasper or through the Icefields Parkway (rated one of the top drives in the world!) so definitely want to come back.