I've just started rewatching The X-Files (man, was the show great back when it was good), I naturally started to think about what games can I play that feel at least somewhat like X-Files. So let's list games like that, shall we?

The X-Files Game (duh)
Alan Wake and American Nightmare (I love those games, I live in hope of a proper sequel)
Condemned (a bit to horror-ish for me, but I still had fun with it).
Fahrenheit/Indigo Prophecy (starts of great, but man does it get stupid once it gets stupid)
Cognition (starts weak, gets really good, ends really damn stupid)
Deadly Premonition (I think, I have not played it yet)

any more ideas?

EDIT, being some of the games mentioned below I think fit best:

Puzzle Agent
Area 51
Outlast
Penumbra series
Gabriel Knight series
Blackwell series

Outlast definitely fits the bill
Resident Evil games

Edit: Uuu, Penumbra games.

Prey

Outlast... wait, didn't I get that in the current Humble Bundle? Damn, thats convenient. Looks a bit scary for my taste (I'm a whimp, yeah) but maybe I'll man up and try it. And I already own the Penumbra games here (a freebie from way back i belive).

What about the Still Life games? They look like they might fit the bill.

It is fairly freaky, and there's a lot of jump scares. Still, if you feel like it's too scary, remember: Most of the time, you can just stop sneaking and just run towards your objectives. Running around a table with a murderous maniac in tow kinda kills the suspense, but I guess that would be a plus for you.

Hmmm, there is one Indie game I liked because the atmosphere keep you tense because you want to know what is happening. I am talking about Montague's Mount. I have not finished the game, so I can't tell if it is related to ovnis, ghost or monsters hahahaha, but the game is cool.

If we want to talk about ovnis, there is a game series that no one has mentioned yed: Men In Black. A little bit childish, but is ok.

Well, I bet the reason it's not on GOG is due to the pitiful entry it has on the community wishlist (less than 500 votes spread across several different entries). Also, in the past the game was released as freeware... which never translates into hard sales when there's an open copy floating about. That being said, the download can be pretty hard to find ever since Midway games folded in the late 2000's. I'd love to see this get released here. I just wonder what's holding it up... Perhaps the soundtrack, since it has so many licensed songs?

https://www.youtube.com/watch?v=xDlzAcp0Sy0


Perhaps Gabriel Knight and Phantasmagoria 2?

I'd also say Pendulo Studios' Yesterday sort of fits the bill. It used to be on Steam, but 2k stopped selling it, supposedly because they "ran out of serial numbers" for it. You can still redeem keys from the retail version there, which was always the only way to get the game on Steam if you're in Germany, for some unfathomable reason.

Call it my own conspiracy theory, but I really don't think the wishlist matters one way or the other. I've seen Spoony's Let's Play of Phantasmagoria twice (and generally I hate Let's Plays). Good times.

That's actually the reason why Phantasmagoria 2 was one of the first games I bought on GOG.

Doom.

And I second the Penumbras, Black Plague in particular.

I'd say Puzzle Agent 1 & 2.
And maybe, maybe ...

Life is Strange?
The Vanishing of Ethan Carter?
Murdered: Soul Suspect?
The Moon Sliver?
Her Story?

Condemned is probobly the best choice.

The second Peumbra (skip the third entry) is a good match. Nah that's crime fiction and not supernatural/scifi.

Cool game! I got to the last level or one of the very last levels but I didn't finish it. It's not a "great" game in my opinion but it was a good bit of fun and tried some different things.Oh and It has Marilyn Manson voicing a main character too.