Basically any MMORPG that I played aside of Ragnarok Online.
It was always the way that my favorite Class/character was either nerfed or just forgotten along the "rebalancing" ongoing, which usually made the game more unbalancing (especially in Dragon Nest, Blade & Soul and Tree of Saviour, not counting in all the P2Win games I checked out for like a week and quickly lost interest in) and frustrating for me to play.
I honestly don't understand how companies can continue to mismatch balancing between characters, I mean it's simple math, you just have to make sure that base utility and damage capabilities are balanced, everyone can do simple DPS calculations and give every similar Class the same damage per second...
Worst game was Dragon Nest, every level cap the game enforced a meta onto the gamers and every time other Classes were in the roster, so you had to reroll everything completely, forcing players to spend hundreds of $$$ to be even viable for endgame content.
Fuu Jellies, P2win costumes and reset vouchers, never going to spend on an unfinished game again.