I picked up L.A. Noire
in the Steam summer sale and am really enjoying it so far. It's basically a classic dialogs-and-clues adventure game benefitting from very good facial animation and with an open world bolted on for diversion in the form of "classic scenes from old cop movies" minigames (car chase, foot chase across rooftops, shoot the perp using the hostage as shield without hitting the hostage, etc.).
And unlike Rockstar's GTA IV
it doesn't run like a dog on PC, either. Well, the DX9 mode does actually, but they put out a patch in February that adds a DX11 mode and that runs like butter on my GTX275.
I worry a bit that the clue gathering part will get repetitive after a while, but if the storytelling keeps being satisfying it'll make up for it.