I agree with you on this, you could make a 2d metroid game and have the obstacles come out of the screen, and even have ennemy's fly "in front" of a character
edit, forgot to name a game series..... definatly metroid.
If I could have any game it would probably have to be Starfox. That game was the first of its kind with its vector 3D'yness, so it makes sense it should come back to be the big game of the 3DS.
The usual stuff that makes me buy nintendo consoles.
Mario, Metroid, Pokemon, Zelda, and anything exclusive to nintendo or probably some awesome new IPs.
I just freakin' hope this handheld console won't fail.