>>14720349
Thief and Thief II, if you're capable of handling older games that look like shit. If you're not, just skip those and play Deadly Shadows. Everyone on Earth shit on NuThief, and to some extent it was justified, but if you play on the highest difficulty and turn off the handholds, it actually does the moment-to-moment sneaking very well.
Splinter Cell: Chaos Theory. Then Double Agent, if you want more. Blacklist is OK. Conviction is shit. Don't bother with the first two games in the series, they're too linear. I say this as someone who played them on release and loved them at the time.
NuPrey allows for some sneaking, but it doesn't really allow for pure stealth runs. Although, the apartments are on a space station, and almost everyone is dead.
Hitman, specifically Silent Assassin, Contracts, and Blood Money. Absolution is garbage. I hear NuHitman is good, but it's got always-online bullshit, so don't encourage them.
That's it, I guess. If you're willing to play other games with sneaking but no apartments, there's also Arx Fatalis and Dark Messiah, The Elder Scrolls, Far Cry, and the 3D Fallout games. There are also the Styx games, which I've heard good things about, but I don't know much about them.
After that, you can join the rest of us in lamenting the death of pure stealth games.