Zardnaar
Legend
4e Essentials felt more like an attempt to do some sort of course correction. 3.5 can be perceived as a cash grab. The total rules update for 3.0 could have been done slowly over the life of the edition I would think. 3e seem like it had legs.
Longest lasting in print if you count Pathfinder.
B/X kinda depending on how you count it eg last product vs officially canceled or Holmes to 1996 etc.