DotA 2: Should have had random items as rewards from matches based on the hero you are playing, instead of entirely random. Also, they should have had in-game currency for their stores rather than just barter and RMT.
Disco Elysium: Thought cabinet should not cost a skill point to remove an already internalized thought.
EU4: More internal realm management/struggle.
WoW: Raising the level cap is always a mistake. Obsoleting content is always a mistake. Worst storyline imaginable.
Heroes of Might and Magic: Conflux in HoMM 3 was lame

i'm waiting