I know that people are just going to say, "look in the last place you played it" or something, but I've already checked all of those places.
We have two living rooms, and I usually play it in the upstairs one, though I clearly remember having it in the downstairs one. I've literally checked the entire house (not including stupid places I haven't been in for weeks).

I've checked the kitchen, the living rooms, my room, the computer room, the dining room, the washer and dryer, and virtually every other nook and cranny I thought I may have put it.

I've checked under the couches and in the cushions. No luck.

D: I don't want to have to re-buy it. My save file is pretty important.