I was also going to suggest
Vancouver and someone beat me to it. Very mild summer, manageable city, extremely clean and friendly, high quality restaurants, good shopping, etc. Furthermore, there are some good day trip or add ons, particularly
Victoria and
Whistler, both of which have plenty of activities and are also relaxing.
I also love Montreal, but you may wish to explore other areas of Quebec for a more pastoral vacation. This summer is the 400th anniversary of
Quebec City and there are lots of cultural activities going on all year long:
http://monquebec2008.sympatico.msn.c...08/?lang=en-ca