sunshine has the best conditions by far, goats eye is has it all and the ski out is really fun. i had a seasons pass in 99 and it was the best $400 i have ever spent. the gunja-ola ride up in the morning is sweet, it takes about 20-25 min. (plenty of time to burn a fat stick and take in the amazing scenery) The best thing about sunshine is the Powder, i remember at least a dozen days of waist deep virgin runs in the early morning.
lake lousie is great as well, nothing compares to the scenery up there, and it's huge to boot so many cool runs and bowls, worth a good two days for sure. however the snow isn't nearly and good as sunshine (fresh powder everyday is hard to beat). the conditions as mentioned, are very similar to ontario conditions (thin and icey in places).
Norquay is the smallest of the three but the steepest and fastest, conditions were always icey. i only went a couple of times because i never wanted to miss the powder at sunshine. if you're into night skiing, norquay is your place, has a really cool half pipe and snowpark that's always fun after some beers and blunts.
get a room in town (banff) that's were all the action is, and you can find some reasonable prices as well. there are plenty of small motels along the strip.
getting to the hills is really easy, there are buses going to all three all day the cost nothing (10-15$) and they pick you up right at your hotel.
have fun, and be careful. banff is 5000 ft above sea level and coming from ontario you'll really feel it in your legs and lungs, keep that in mind when you want to sqeeze one more run in. i saw plenty of injuries at the end of the day from tourist trying to get too much in.