In Ottawa I like the Ottawa Folklore Centre. They've recently moved to a new, more modern facility. Personally, I think the old one had more character (uneven, bare wood floors), if a lot less room. However, they were really running out of room, especially for the music school. They have a great staff and a nice selection of new and used instruments ranging from starters to vintage (primarily acoustic). I often stop by to just browse around, see what's new etc. I usually find a hard to find CD or something else I can afford.