This question already has an answer here:
With new patch(2.0) you have different difficulties and despite which difficulty you are on, you are guaranteed a legendary drop when you finish the quest for the first time. And you can reset quests to get this first-time reward. Also, it seems that all legendaries can roll a lvl 60 stats(got a few low level legendaries with 400-500 stats).
So the question is: which difficulty should I play for the most/best legendaries? Does Torment give you better drops? I can farm Torment without many problems, but it seems that Normal is much more rewarding in terms of legendary drops because I can just fly through it.
It also seems that you can reset quests any number of times. So a small addition: Will I get more/better legendaries if I finish the game 2-3 times on Normal than if I would finish it once on Torment difficulty?