1 night in Banff
If you are staying on a Friday Nite or Saturday Nite, I would say the brunch at the Banff Springs. They have a spectacular brunch on the weekends.
For dinner, I would say Fuze
If you are going on a Friday/ Saturday, I would say head into Canmore for drinks at Muriettas (They usually have live music and dancing)
I went to Bison Bistro on Bear St in Banff for brunch this past weekend. I really enjoyed the food and the atmosphere. In particular, I really enjoyed the bison burger. They have breakfast items as well such as duck confit benny, etc. Brunch in the main dining room upstairs is only available on weekends. However, their lounge downstairs (which used to be the General Store) is now open all day for more "casual" dining (not that it was that formal upstairs..)
My suggestion would be Le Beaujolais or Eden (at the Rimrock Hotel) in Banff.
At Le Beaujolais, my husband and I have never had a bad meal to date. I would go with the tasting menu but stay away from the wine pairings. Maybe start with a nice glass of white with the appetizers and then choose a bottle of something to go witht the rest of the meal. http://www.lebeaujolaisbanff.com/
Eden is also a favorite. The tasting menu here is out of this world and I would argue comparable to some of the finest restaurants in the world. (ie Per Se, NYC). The service is par none, the ambiance is beautiful - looking towards a mountain, and the food is amazing. http://www.rimrockresort.com/eden.html
We've been to Fuze but we find the service to be inconsistent and the food to be 'nothing special'. I would compare it to a little better than an Earl's or Cactus Club. If that is what you are looking for, then this is the best choice. It was OK the three times I've eaten there but much better than going to a chain resto.
If you're looking for something casual, yet interesting try the Grizzly House for fondue. It's a blast. http://banffgrizzlyhouse.com/