I'm looking for a game

Dark Souls is challenging and conveys an amazing ambience.

Ah you've probably already played this, and it ain't really puzzle-y, but it's still one of my all time favorites: Return To Castle Wolfenstein. Other mentions;
MAX PAYNE 1 AND 2 is also really good... Haven't played the third game. Morrowind/Oblivion/Skyrim also good, Binding Of Isaac, Alan Wake, Darksiders, Deus EX franchise...

Open world RPG game like Fallout or TES.

Play Paradox strategy game like heart of iron , Crusader king...etc if you want your soul get suck into a different era for ...several week.

A other choice will be Totalwar series, ..you will spend a lot of time for it.. believe me

OR some 4x game, classic like Space empire, Galatic civilazion, Civilazion .....or newer like endless space, stardrive, sword of the star

PS: don't blame me if you begin to say something like, "For the motherland", "deus vult" or "For the glory of Rome" after you play those game

Skyrim + DLC + Infinite mods how someone gonna finish this game?

also : THIS !!!

Bioshock Infinite / BioShock 1 / Witcher 2

If you're looking for amazing adventure game, then Okami is your choice. Get PCXS2 and emulate it, if you can't get a hold of a PS2 copy.

I used to play Freedom Fighters, but I don't know where to find it nowadays.

the game of life

dead space

I have many ideas that will satisfy you:

• TES: Morrowind
• Fallout New Vegas
• GTA San Andreas
• The Witcher
• Civilization IV
• Baldur's Gate
• Vampire: Bloodlines
• Alpha Protocol

Have you tried the Geneforge series? Each individual game will last you roughly 50h per playthrough, and there is a good amount of replay value in them.

The Darkensang series is also good. Not as demanding on the brain or as much game for your money, but still very good.

Majesty: the Fantasy Kingdom Sim. Plenty of replay value, a decent amount of levels, and really fun.

Republic: The Revolution. Different, interesting gameplay, really good soundtrack.

Daggerfall. So you said you wanted a game that won't be over in a day or two?

Star Wars: Knights of the Old Republic

Star Wars: Knights of the Old Republic II

i enjoyed both games and have over 100 hours in each of them. one playthrough takes approximately 40 hours for each game

Tomb Raider series.

without reading other comments or at your game library, i 1000% suggest Don't Starve.
your descriptive requirements is a perfect match for don't starve!

SpaceChem is a really awesome puzzle game. It starts out seeming kind of simple, but after an hour or two, it zooms out and suddenly it's this massively complex awesome thing. You definitely have to use your brain; the puzzles increasingly get mind-bogglingly complex. It's also quite long (I'm twelve hours in, and I'm pretty sure I'm less than halfway through) and has no online whatsoever. I heartily recommend it.

Try the Total War series. Medieval 2: Total War took me about 80 hours per playthrough, that is conquering the whole map.

You can play Skyrim tho.

You want a roguelike. My favourite is ADOM - Ancient Domains of Mystery, or as TotalBiscuit called it, Ancient Domains of Masochism.

Fallout 3 or New Vegas

ill recommend stalker just because im a diehard fan,

but seriously shadow of chernobyl really took a long time to finish, specially considering how hard the game is even on the start, no mercy, like the first mission you can get killed in 2 shots out of a sawn off shotgun in middle range its like a role change the enemies become the bullet sponges and you become the puny guy who needs cover all the time, and it doesnt get as easy as you go by, the mercenaries, zombies and monolith bastards are as tought as nails so its always challenging you.

i also recommend call of pripyat, even thought is more easy, the atmosphere and the missions are awesome too.

Any of the Elder scrolls games, Witchers, Star Wars Knights of the Old Republic games, several others

• Fortix
• Deus Ex series
• XCOM Enemy Unknown
• Batman: Arkham City
• Bastion