We've all gone over how some games are horribly butchered when brought over seas, we've all seen how unplayably bad that exile 2, bayou billy and double dragon 2 were when they decided to tweak the games for us release...
we've all seen how stuff is just inexplicably removed from games like lifeforce contra and karnov.

but how about when a game is made BETTER when it comes over seas?

a few that come to mind:

Zelda 2:
fixed the experience system, added more tile sets for dungeons, added a new boss for level 5, tweaked gained exp to make more sense and enhanced graphics.

metroid + kid icarus
added a second quest option to both games, metroid got an extra ending (armourless samus)

final fantasy 7
two new super bosses, new materia + weapon for yuffie

dragon warrior 1
much better graphics . better interface. save feature

dragon warrior 2
new opening story +save feature