My vote would be go to revelstoke and kicking horse. Revelstoke's area is more of a ski/snowboard bumb town. Everyone that like there, basically just there to ski and snowboard. Now revelstoke is a pretty small mountain, but the powder is just amazing. Revelstoke is also expanding in the next couple years, its being referred to as the next whistler. So you should go check it out before it becomes to commercialized. Just an FYI, there is no terrain park on the mountain.
Kicking horse is a pretty massive mountain, with a lot of bowls. If its a powder day, its great for snowboarding. If its not a powder day, it sucks for snowboarding.
Sunshine, lake louise, and banff. I like to call lake louise and banff, more hills for forigners. Because those are the places where lot of people from Europe and Japan come to visit. I would avoid Mt Norquay, at all cost, because it just sucks. I do go to lake louise quite a bit because it does get less busy, but it can become very icey here. Sunshine is more of a Calgary local site, everyone I know from calgary goes to Sunshine. There are spots that are good and spots that are bad on the mountain. Terrain park is slowly getting better. I am starting to like sunshine more.
Fernie, is a hit or miss. It can either be the best day or the worst. Fernie, will get rain storms and be shut down for avalanches.
Also none of these places have a half pipe.
I can't comment on Whistler, because I haven't been there.