Lost Alpha is the second hardest game to run from my experience, the first being Dragon Age: Inquisition.
While I think very little of Hitman: Absolution, Thief, and Deus Ex: The Fall, I strongly recommend Hitman: Blood Money, Thief Gold (with a widescreen mod, Thief Gold HD Texture Mod, and Thief Enhancement Pack 2.0), Thief II: The Metal Age (with a widescreen mod and Thief Enhancement Pack 2.0), and Deus Ex: Human Revolution Director's Cut. Everyone will also recommend the first Deus Ex, but I actually haven't gotten around to playing it yet.
I'm currently playing Dragon Age: Inquisition... approaching the 120 hour mark and I still haven't finished my first playthrough. It is definitely most deserving of Game of the Year 2014, and it's the most ambitious single player game ever made without a doubt.
Dragon Age Origins was an amazing game that I replayed 4 times in almost a row. Dragon Age two was a game I barely managed to finish (it was more pain than pleasure, the only thing I liked was using a specific magic combo that dragged everyone to me, then a ground slam, then an explosion that sent everyone flying away).
Allow me to explain: Dragon Age 1 was new, everything had to be learned from 0, and once you did, you felt powerfull because not only the characters were stronger, but becasue your control and understanding of them was higher as well.
In dragon age 2, you start from scratch again, with new characters and new spells/skills.
This would be ok if youd get the same character intro and story and tutorial etc as in the first game.
In dragon age 2, its like: you know all there is to know, but everything is different now, but you still should know.
I dont see much of a point to call the game dragon age 2 when there is so little correlation with the first game.
Im gonna take my time before I consider dragon age inquisition, as it seems yet another story almost by itself.
The older games you mentioned are so so for me. I tried all hitmans and still love 47 most (main reason is on how the missions work). I played missing link and original HR, so I guess almost everything will already be covered in directors cut, but ill try it anyway. All nice and good, but get boring once you realize that the smartest move is to always use non-lethal takedows since it gives higher XP (from my point of view its harder to use guns and headshots, especially without raising an alarm than to use silent takedows, but ok).
Thiefs Ill leave for later. I tried the last one for about 35 seconds before uninstalling it. I might try it someday but it looks like a terrible game. The first thing I did was running after a girl and basically pressing space.... for 30 seconds... Dark Messiah of Might and Magic has a similar part but it looked far better: You knew why you were chasing the ghoul, and that it was important to catch it and that you could actually FAIL. And you had to find the way yourself, and do it fast enough to not loose the ghoul.
So... basicly if you did it, in first try, you felt like you were good. Pressing space while holding W... not so much.