Trauma Center: Under The Knife has been, by and large, picking up pretty decent reviews. A combination of the children's board game Operation and a manga retelling of the soap opera General Hospital, this game requires timing and precision I haven't had to flex since Ninja Gaiden. Except now I'm doing it with a stylus, hunched over a table, and there is a "person" who is relying on me to pull a piece of glass out of their heart that has got to be at least a foot in length.
Thinking about it, I'm quite amazed something like this didn't come out sooner. You could easily do a PC version of this with insane graphics, and a story or something. Add tablet support, and you've got yourself a winner.
As it stands, for the Nintendo DS it could be your cup of thing. And as they say, it's getting pretty decent reviews.