Space combat (Rogue squadron, Tie fighter)
Space sim (Frontier first encounters style)
Big budget 2D or 3D adventure games (Grim Fandango, Dreamfall longest journey, Riven)
Big budget cinematic platformers (Flashback, Another world, Oddworld)
Rally racing (Europe still has WRC, DiRT is not rally anymore)
Flight sim (about time consoles get one)
Big budget top down couch co-op rpgs (Baldur's gate dark alliance style)
Survival horror (Silent hill 2, Siren blood curse)
Imaginative RTS games (Populous, Dungeon keeper)
Adventure games have been surprisingly alive and kicking over past few years (check out http://www.adventuregamers.com/). But, I agree, as my one of my all time favourite genres I would love to see them back in mainstream with big budgets - let's keep fingers crossed that Tim Schafer's game succeeds and manages to persuade Ragnar Tornquist it's time for him to stop messing with MMOs and finally make Longest Journey 3.
BTW, great choices for "comebacks".