League is fun... I think
Instead of looking at League of Legend's as one continuous game, what if we broke it into sequels.
If we perceived current League of Legends as "League of Legends 3" we might actually enjoy the game a lot more. Most sequels aren't seen as an improvement until you go back and try to play an older version.
This is a completely different game than it was in Season 2 when I started, and I love it. Because I realize I'm not playing the same game.
Proof is in the new players and how much they love the game. In all fairness, a good percentage of players I've introduced to the game also discovered DotA2 and no longer play League. I tried DotA2, I hate it. Anyways, new players don't have anything old to compare it to. Therefore, their opinion is based solely on the version they're playing at the time, and they like it.
The best comparison I can make is Fallout 3 being better than New Vegas and 4... until you actually go back to play FO3 again.
Unfortunately, we don't just have a copy of LoL S3 lying around, but I'm sure after 50 matches, I'd prefer the current version. I think S4 was the season they took out EC, which lead to a bunch of wild Olafs and Warwicks dominating every match. Those times aren't missed for me.