Surprisingly none of these. If I included the spin-off, it would be dead last. If it wasn't for Ana and Jafar, the show wouldn't have been able to keep my interest.

I've never seen the spinoff but, regardless, I agree with this placement. I still haven't even finished the season because I thought it was so bad.

I didn't know there was a spinoff. What is that about?

It's called Once Upon A Time In Wonderland. It's basically about Alice (Now grown up) trying to find her boyfriend that she thought was dead, who also happens to be a genie. She has the help of the Knave of Hearts/Will Scarlet. There are also two villains after the genie's powers and need Alice to make all three of her wishes in order for them to use its power, those two villains being The Red Queen (Later revealed to be Anastasia Tremaine, Cinderella's step-sister) and Jafar. The spin-off was only 13 episodes long and the only reason I watched all of it was for the villains (Especially Anastasia).

least favorite by far!

Season 1 (My Favourite)
Season 3
Season 2
Season 4
& Season 5 is my least favourite