Dead Space

The Witcher

Battleblock Theater, Bioshock 1 and 2, Risk of Rain.

Bioshock trilogy, Max Payne 3, Mirrors edge, Killing Floor, L4D2, Dear Sther, San Andreas, New Vegas

DWARFS?!, saints row IV, counter strike GO, borderlands 2, Killing floor, The Incredible Adventures of Van Helsing: Thaumaturge,

Deus Ex: Human Revolution

And with so many different suggestions, you'll still not be any wiser ;)

Looks like you haven't touched Far Cry 3 yet. That game is a lot of fun, play it!

Looks like Far Cry 3 or Mark of the Ninja good choose.

Hotline Miami, Mirror's Edge, Saints Row IV, Dishonored, GTA: VC, Mafia II, Super Hexagon, Receiver and Mark of the Ninja.

TBOI: Rebirth!

you have battleblock theater, bioshock 1 & 2, flatout and the witcher but you haven't played them yet...

BLASPHEMY!

Going down your list with 0h playtime I recommend: Monaco, Super Hexagon, GTA VC/SA, BattleBlock Theater, Bioshock (!), Bioshock 2, Dead Space, Deus Ex: GOTY, Deus Ex: Invisible War, Half-Life 2: Episode One & Two (!), Insurgency, Magicka, Mark of the Ninja (!), Metro 2033, Risk of Rain, SpaceChem, Stronghold Crusader, The Witcher: Enhanced Edition,

Half-Life 2 series. I see you don't have any playtime on them.

Morrowind is IMO the best RPG of all time, although the first time I played it I found it hard to start because I had no idea what I was doing. Picked it up again later, started reading what everyone has to say etc and fell in love with the great and immersive world.

Every choice you make matters, choosing a guild makes enemies which means you cannot join some other guilds. Every dungeon is unique and nonscaling, meaning you actually get a feeling of becoming stronger. There are no essential npcs, although killing someone important for quests will trigger a message. There's so much to see and do, it's amazing :P

The Cons would probably involve stuff like outdated graphics, 'dicebased'combat and poor lvling system and a HUGE journal, but all those points are not breaking the game for me ;D

11/10 GOTY of every year

Far Cry 3

Deus Ex: GOTY Edition. No other game in the series has surpassed it, and I'm sure you've enjoyed Deus Ex: Human Revoluton (still not as good as the series' entry game).

• Portal 2 (I doubt you finished it with so little gameplay time on record.)
• Bioshock Infinite (Same reason as above.)
• Mirror's Edge
• Deus Ex: Human Revolution
• Mafia II
• Spec Ops: The Line
• Far Cry 3
• Mark of the Ninja

Fallout: New Vegas.

You seem to have just started Morrowind and not done anything else. So that's my recommendation. Remember to mod it!

• Deus Ex: Game of the Year Edition
• Half-Life 2 (assuming you already beaten Half-Life)
• Broken Sword 1 - Shadow of the Templars: Director's Cut
• The Binding of Isaac (but keep in mind there's the new one already, so consider buy that instead)