I'm looking for a game (or 2) to play during my two week Christmas and New Years break. I'm tending to play an FPS, but am open to other perspectives. Games I've played during this period in other years: Far Cry 3, Far Cry Blood Dragon, Bioshock Infinite (minus DLC), Sniper Ghost Warrior 2, Tomb Raider (2013), Dishonored, Borderands 1 (also played 2).

Stealth mechanics, some tactical thinking are welcome mechanics, but not mandatory. A decent enough story, if it's a good all the better.

Also it needs to run on my laptop:
intel i3-4005U 1.7GHz
GeForce 820M 2 GB Dedicated VRAM
4GB RAM

Thank you for your help.

One of the S.T.A.L.K.E.R games (preferably Shadow of Chernobyl or Call of Pripyat, Clear Sky is somewhat weaker, but can also be fun, if you like a challenge).

Deus Ex?

Works wonderfully with either GMDX (+Veronica's Brightness) or Revision mod to get a 1080p and some other nice extras.

I don't have "Christmas break"; I have paid vacation.

Still Mass Effect 2... but I've been busy setting up a new Shield TV Pro (2019) the last couple of days.

I can't recall any problems with shots not hitting their targets. iirc something like that might be an issue on lower difficulty levels, but I played on the 2nd highest and didn't have any noticeable problems. Can't say anything about mods tbh (never played them), but there are lots of them, so I suppose you can customize the experience the way you want it.
As for horror: Depends what you mean by horror. There are some creepy sections in dimly lit underground buildings and the like, but it isn't the focus of the game. Shadow of Chernobyl and Clear Sky at least actually are mostly about firefights against human enemies (Call of Pripyat a bit less so, though it still has them).

I really enjoyed the Mass Effect Trilogy, even the third one (with the exception of the 3 color finale).

I read they changed the original ending with some free DLC. I wonder... is the new ending used when the DLC is installed and the old ending unavailable? I don't want to google it out of for fear of spoilers.

Deus Ex Human Revolution Director's Cut

Great combat, stealth, and decent story and pretty visuals. You can get it dirt cheap now.

The "Legacy of Kain" series, if you like a good story with deep lore and aren't set on a game having the latest graphics and all that. I started playing Soul Reaver one Christmas break many years ago and it was probably one of the best decisions I ever made, gaming-wise at least.

Already played it, and loved it :)

https://www.mobygames.com/game/home-alone
I actually played this in the 90s!