I may be biased.... as I live in Beautiful British Columbia
It comes down to what you want to do and see?? Do you want to be able to relax in the wilderness with small town civilization? Do you want to be in the hustle and bustle of the big city (Vancouver)? Do you want to visit our beautiful Capitol for a little less hustle and bustle, but still many sight seeing options (Vancouver Island - Victoria)? Will you have a car?
My top must sees would probably be:
Vancouver - Waterfront/Stanley Park
Okanagan (Kelowna, Shuswap)
Whistler
Banff (which is actually on the border of BC and Alberta)
Vancouver Island - Victoria, Tofino, Long Beach area
There are several resorts in the Panorama area as well.... They look amazing, however, I have never been!
I grew up in a suburb of Vancouver, there is no shortage of things to do and see all over Metro Vancouver and the North Shore areas...
I now live in the beautiful Okanagan - less busy but also no shortage of things to do and see!