And why?
I'll offer some options (all of which make me gaze dreamily into the distance):-
1. The next ZELDA
2. The next big macho "gears of war" or PC FPS type game using a big macho engine like Unreal3
3. A Wii game directed towards a larger audience, say women for example?
4. A Pokemon MMORPG on Wii (a real WOW killer if ever there was one)
5. Animal City (a sequel to Animal Crossing but based in much large townscape - each neighbourhood merges into someone elses in online play)
6. Half Life 3 (not a HL2 episode)
7. Final Fantasy 13 for PS3
8. A sequel to shadow of the colossus for PS3
9. MGS5 - with an online battlefield mode with designable characters
10. A new mario game on any ninty platform
11. An EA sequel
12. Something else