i always thought chrono trigger and final fantasy tactics both needed proper sequels, not that far out in left field crap they tried to pass off as sequels. after all these years i still wait patiently. stupid square.
One game that really needs a sequel is Beyond Good and Evil
Yes! Why does Ubisoft insist on breaking my heart with their lack of BG&E2 news? :(
Other than that, Psychonauts reeeally needs a sequel, as does Okami (though now that the ds spinoff is coming out I'm much more hopeful for a full sequel).