If you are budget conscience, try the Rosedale on Robson. It's within walking distance of Rogers Arena and is decent. All the rooms as suites, and it has a functional pool and hot tub for the kids. It's in good area.
If you are OK spending a few bucks, the Westin Grand is excellent and is very close to Rogers Arena as well. The pool is an outdoor pool though - though they do keep it open year round.
I know that the Sandman is also an option, though I have never stayed there. The Hampton is also close but I have no personal experience there either.
To be honest, use Expedia or one of those sites and just cruise around until you find a price you like. Most everything in downtown Vancouver is within walking distance......just some walks are further than others.