Season 4 is my favorite Naley season!
Although I think season 3 has the best scenes.
Season 1 is also great for Naley!
In season 6 they have never a fight or anything like that = I ♥ it!
Season 2 and 5 are the worst seasons for Naley but I think that season 5 is better than season 2.
I hope this helped you a bit.
I'd say 3 is really good overall for Naley
Season 4 is adroable though cause you see them becoming parents and stuff, so it was also a great Naley season.
The latest one, 6, was great. There were no fights, just good old cute Naley, only problem is there wasnt much love scens lol untill 6.23 ;)
Hope this helps