I've been trying to find one throughout the Steam summer sale and come up dry, and now I'm out of money until the 15th. Hopefully y'all can help me find a good one before the winter sale. Here's a rundown of what I've tried so far and what I've liked and dislike about them:
Arkham series
Positive: I played through Arkham Knight a few years ago, and it made me fall in love with the genre, or at least what I wish it were. My ideal game is an endless series of well-built, challenging Arkham-style stealth puzzles I can just binge like sudoku with no brawling and no plot. I've now resigned myself to just trying to get through the rest of this series again before I spend more money. My wife also likes watching it.
Negative: I made the mistake of playing the last game first, and now the others feel disappointing and half-baked. The series got harder as it went, and Arkham Knight was still a little too easy, even on the hardest setting. Brawling scenes are monotonous and make my hands hurt. I've heard bad things about Gotham Knights, so I'm not about to spend that kind of money.
Alien: Isolation
Positive: Almost as close to what I want as Arkham, but in the opposite direction. Still should probably give it another chance.
Negative: Instead of padding it with combat, they padded it with tedious walking simulation. Also too dark. The glare on my living room screen makes it hard to play during the day.
XCOM series
Positive: XCOM 2 is another of my favorites. I'd like to know what recent turn based tactical games in this genre are good and emphasize stealth. And maybe local multi-player? Although those are kind of at cross purposes.
Negative: Once again made the mistake of starting at the end of the series with War of the Chosen, and now I have trouble getting into the earlier games. Chimera Squad was also very underwhelming.
Bioshock series
Positive: You know, I should probably just get back to Bioshock, come to think of it. Don't know why I didn't quite finish the first game.
Negative: I guess the only thing stopping me is that I'd want to finish the first one before getting to the sequels, and I'm not sure I still have my old save, and if so I'm dreading jumping back in at the end when I'm rusty. But no, I need to just finish Bioshock. I'd like to do a "good" playthrough, anyway. Are the sequels as stealth-oriented as the first one, though? I've heard you play as a Big Daddy in the second game, and that doesn't sound stealthy.
Hitman series
Positive: So close. I got the pre-reboot Hitman bundle on sale, and the overall playstyle seems like exactly what I want in theory.
Negative: Yet so far. First off all, the earliest titles are just too clunky and old fashioned for me. Don't get me wrong, I'm not a graphics snob, I can still enjoy an NES game. But that era between Doom and Portal or so, when they were fumbling around trying to figure out how to make a 3D game, I just don't have the patience for that.
I tried Absolution and it was tantalizing but obviously flawed. I looked up some reviews to see if it got better or worse, and it turns out it definitely got worse.
It appears that what I'm looking for is the 2016 reboot. Problem is, IO Interactive doesn't want my money. They took the first two games off of Steam, folded them into the third installment, and charged $69.99 for it. This makes me feel morally obligated to pirate these games and see how good the "Peacock" experience is. So now I have it torrented and I'm waiting for another ten+ hour window when no one else wants to use the computer and I can devote every single clock cycle of my long-suffering i5-2500k to decompressing Hitman, and hope it doesn't have a random error eight hours in like it did last night.
Deathloop
Positive: Runs surprisingly well on my old rig, even with a video playing on the second monitor. The graphics on reduced settings still look way better than what I'm used to.
Negative: I had such high hopes for this based on the reviews, but it's been my biggest disappointment so far. How is this even a stealth game? I try sneaking around, but then someone spots me, and instead of that being game over, I can just Doom my way through the rest of the encounter, and that works out more or less fine. Does it get better? I'm afraid to see for myself because I don't want to put on so much playtime I can't return it. My wife also hates it because it's too violent. I was intrigued by Dishonored and Prey, but they're from the same studio as this garbage, so now I'm leary of trying them.
Assassin's Creed series
Positive: Seems too obvious not to include. I don't think I've ever actually laid hands on a controller when it was playing, so I don't want to be too hard on it.
Negative: Every time I've seen it played, it just strikes me as dumb. The Da Vinci Code shit is dumb, the puzzles are boring, the gameplay is gimmicky and dumbed down in all the worst possible ways. They're obviously similar to Arkham and Hitman games, but I've never heard someone say they were better or harder, so I've never bothered giving them a chance.
Conclusion
I gather that designing good, challenging stealth puzzles is an extremely difficult feat of game design. So what developers tend to do is spend as much time as they can afford on stealth puzzles, and then fill in the rest with action, exploration, and plot when the deadline looms. But there's so much out there, I'm sure there are hidden gems I can track down before winter.