The french series "banque du canada" are the most desirable. They are very hard to find especially in the higher denominations.
The french issue of the $25 is extremely rare, i think there are no more than 100 or so that remain to exist mostly in heavily circulated condition.
Has anyone ever seen a french issue of the $50. I am hoping to acquire one in G or VG later on this year. I heard they are even rarer than those $25 french notes... is that true?