Here are my personal comments based on observation or actual experience.
Presumably you're looking for major dealers in the Vancouver area who have a reasonably large selection of used bikes at any given time.
I had a good experience buying a used Kawasaki at Pacific Yamaha / BMW (pacificyamahabmw.com).
Down the road from them is Richmond Motorsports (richmondmotorsport.com) which also seems to have a fair used inventory. I've never dealt with them.
The above two are suburban.
Carter Motorsport (cartermotorsports.com) is a Honda dealer which always seems to have quite the fleet of used motorcycles. I've had repairs and servicing done there for multiple bikes. They are quite professional. Two locations, one in the center of the city and one suburban.
Finally, Modern Motorcyle (modernmotorcycling.com) is a small, family run Suzuki dealership, which has a following for service regardless of the brand of bike you have. Not a large inventory of used, willing to deal, knowledgeable generally. Located in the city on one of the more interesting streets (walk a few blocks north).
There are many other dealers, of course.
The usual suspects are popular here for serious travelling...the BMW dual purpose models, KLRs, Vstroms....quite a lot of choice but it's not Europe.