My personal ranking of leagues from best to worst

1.Johto League
+We could watch all Ash games
+Ash vs Gary happening at least in an epic way
+Some interesting rivals
+Ash not losing in a wtf way
+Diversity of Pokemon
-Some random stuff like Kingler getting KO'd by Voltorbs

2. Hoenn League
+Most 6 vs 6 games (3 games)
+Some interesting preliminary games; we could watch all of them
+Interesting rivals
+Glalie rampage
-Losing against a freaking Meowth
-Hoenn team wasn't fully developed at all (still not Sceptile)

3.Sinnoh League
+Most important league regarding strategy and abilities
+Ash vs Paul has been best battle ever
+Some interesting preliminary games
-Missed some tournament games (that Snorlax Hyper Beaming in round 2)
-Sinnoh team battling only in one battle, rest of it was Hoennfest
-FUCKING TOBIAS AND HIS FUCKING LEGENDARY POKEMON

4.Kalos League
+Interesting rivals
+Great Pokemon (Greninja)
+Pikachu being the level 100 rat it is supposed to be
+Ash reaching the final and not losing against some wtf stuff
-Too rushed; we freaking saw Ash first complete game in semifinals
-Too short
-Sometimes Ash opponents were more important than Ash
-Basically, Kalos League = 2 games

5.Kanto League
+First league, magic moments like that Kingler rampage
+Bellsprout; Muk
-No 6 vs 6 battles
-Ash vs Ritchie was fucking retard
-We missed entire round 2 and almost round 3

6. Unova League
+Diversity of Pokemon used by Ash
-Main rival was beaten in round 1, in freaking 1 vs 1, wasted potential
-Missed some rounds; previous rounds were basically that 1 vs 1, and the 3 vs 3 against Stephan
-Entire Ash vs Cameron; losing against a noob who was only using 5 Pokemon 'cause he thought it was 5 vs 5
-Only one 6 vs 6 and was that Ash vs Cameron bullshit
-Sense of regression compared to previous leagues