I am ashamed to say it, but... I have not seen any of Eastern Canada so I cannot say with any kind of certainty.
- I hear Toronto is nice if you like big cities.
- Montreal and Quebec city are beautiful. (I'm going to there this summer)
- Maritimes have a very unique Canadian culture.
- Prairies... They have their own charm, but I wouldn't make it a destination. I lived there for my first 18 years and have never been back since I left.
British columbia is what I know the best and it all depends on what you are looking for.
- Unless you are a skier, come in the summer months.
- Vancouver is beautiful but expensive and can be a bear to get around. 2 nights is all you need to hit the usual spots.
- My personal favourite is Vancouver island. Victoria is a huge tourist trap in summer, but it is a beautiful city with lots to do. It is expensive too.
- If you want wilderness, head to Tofino on the west side of the island. It is still the wild west coast with some amenities. The drive can be sketchy but worth it.
- Whistler is another tourist trap, but again... There is a ton to do and worth a couple nights.
- The interior of BC is also worth seeing, but vastly different than the coast. What I might suggest is flying into Calgary and driving to the coast with a stop at a bed and breakfast in Naramata. Do some wine tasting and soak in the views. The drive alone has lots to see and marvel at.
- If you want to make it an epic trip, do the drive from calgary to Vancouver, book an Alaskan cruise out of Vancouver to Juno then you can fly out of Vancouver back home. I have never taken the cruise but family members have and loved it, but they are of the generation that likes cruises.
Cheers!