A little late to this Toning party, but I would like to add something if I may.
The toning on US Morgan dollars is something to see, (IN HAND) if you have not seen one before. These coins, and the history of storage makes for a great story and provides some legitimacy to toning which is natural. In the 1970s a massive amount of these where dipped or discarded. (the toning combined with the amount of lustre is truly spectacular, and rarely seen in Canadian coins.) Most of the toning in recent Canadian (1940s to 1960s) coins would probably be considered album toning and general have the same characteristics.
I pretty much only buy coins that have some degree of toning present. I'm not interested in 70+ year old dipped coins with dirty rims. I find them repulsing actually, and "A LOT" of Canadian coins have been dipped!
Cameras today have a difficult time show the toning, "and lustre" at the same time. Very difficult to do.
Hard to beat the toning possible on the nickel nickel series, especially the George VI coins. Radiant green or steel blue - amazing toning when you see it. But there are lots of great coins in this thread. I still meet purists who disdain toning. Their loss.