As a sort of spin off from this topic:
http://www.abandonia.com/forum/index.php?showtopic=5036
What sequels do you think were superior to the originals (or even the previous sequels) and I'm talking gameplay, and potential to do things within the game world here. Not just prettier graphics and sound?
And Why?
My personal choices would be:
1) GTA3 - The leap to a fully 3d world from GTA2 opened up endless possibilities for more fun.
2) C&C RedAlert2 - More tactical, better balance of units.
3) Diablo 2 - Much more to do in the game, better player / enemy balance... And great online play.