So poll + Title should say it all.. what do you think is the most improved sequel..

Note: I get people haven't played all games (or atleast most) but try to choose from the games you played.

I hated Uncharted 1 but love Uncharted 2.

Assasins Creed 2 fixed most of the problems from the first game and it was overall just better.
I'll give a mention to Uncharted 2 though, just because they added so much to the second game.

resident evil code veronica  -----> resident evil 4

this does not imply that code veronica was a bad game

Killzone 2?

Zelda - A link to the past.
Super Mario World.
Super Metroid.

The change from 8bit to 16bit was epic. Wowed more than anything before and after.

uncharted,killzone in my view.

Probably Wii 2. It fixes all the problems everyone hates about the current one.

Red Steel 2

Assassins Creed 2. Enjoyed the second, absolutely hated the first.

And recently I'd say Just Cause 2.