Single-Player games that you have an unreasonable amount of playtime in?

Like, you've been playing it for so long that there's no way you haven't already done everything already.

My Mass Effect trilogy run is actually a little above 1000 hours, because I keep replaying it over and over.

There's nothing in that game I haven't seen, I just... really really like it, and whenever I don't know which game to play, I just restart Mass Effect again.