Here's a picture of the building that formerly housed Kelly's Leather. I am not sure when the business closed; I just remember it being vacant. The building was in very rough shape before it was demolished, but it was unusual and a bit imposing (I think this part of Granville is one of the few parts of Halifax with a larger city feel):
http://www.halifaxhistory.ca/Kellys.htm
Early TD tower renderings showed this facade preserved as part of the redevelopment. Had the facade been stabilized for a while and preserved I think it would have added a lot of architectural interest and could have become a nice retail space.
There's a larger list of demolished buildings here:
http://www.halifaxhistory.ca/Vanish.html
There's a handful of losses on that list (Kelly, YWCA facade, maybe a portion of the infirmary, maybe the former Simpson's) but a lot of them were not great. A few, like the old Dal management building, were awful. The old generating station I would argue is a great example of adaptive reuse rather than a loss.