Most improved sequel in your opinion

[The Ghost of RubangB]

No More Heroes 2: Desperate Struggle.
Street Fighter 2: The World Warrior.
Wii Sports Resort.
Mario Kart 64.
WarCraft 2: Tides of Darkness.
Diablo 2.
Mega Man 2.
Teenage Mutant Ninja Turtles 2: The Arcade Game.
Mortal Kombat 2.
Star Fox 64.
The Cheetahmen 2.