Over the years I gave this game try after try. And one of it flaws had been: No repair function for items. Which was the main reason why I stopped playing (uniques were senseless).....
My machine isn't exactly powerful (i5 3,2 GHz + 9800GTX+ 512MB) and therefore I look for a mod that focuses on gameplay improvement ;)
Any recommendations?

EDIT: Well I haven't tried it yet, but this seems reasonable:
http://www.moddb.com/mods/old-good-stalker-evolution/features/ogse-features-and-changes
EDIT2: Well it seems like it isn't compatible, the game doesn't start anymore :(
EDIT3: Crashed seem to be related to the game version. Will try a down grade and report again ;)

Try "Complele" mods series... In "Complete Mod" for Shadow of Chernobyl you can repair weapon or suit in two places (Bar and Freedom Base) or by using special tool which you can find in dead bodies...
Sorry for my english

Here's the Guys site for the Complete Mod series for each game. Some of the best mods to me.
http://artistpavel.blogspot.com.au/

Stalker Soup Some kind of huge assimilation for the gameplay of all games included content that was planned by the developers but lacked time or resources to make it happen.
Misery mod A more realistic, challenging take on Call of Pripyat.

Warning: Both requires a monster computer even by todays standards.

Overall - Stalker Complete series is decent. It improves the graphics, adds new features, without changing the game too drastically. However, it's important to mention, that you shouldn't use Stalker Complete for Call of Pripyat, as it breaks the game.

Stalker: Shadow of Chernobyl
- Stalker: Complete
- L.U.R.K. (this is mod is for advanced players, already familiar with a game)

Stalker: Clear Sky
- Clear Sky Complete
- MYSTERY

Call of Pripyat
- AtmosFear
- MISERY

Just curious to how it breaks it because I finished a playthrough a while back with it and did not encounter any sort of issues.

I've finished the Call of Pripyat twice with the Complete Mod never had any issues.

I don't like the "Complete" Mods, at least the Weather Preset in SoC is most of the TIme like Disneyland. And because of that, i removed the Complete Mod after a few Hours.

Try instead better Autumn Aurora 2. It's so much better and the Weather increasing the Atmosphere on a New level.

Absolutely Amazing!

Yeah the Complete series is one reason why I'm interested in trying out the Stalker games, but my copies are old discs I got with some gaming magazines and don't know how they work on a modern setup or what updates they have.

I'd be more interested to know what mods work with the GoG version. Does it differ from the Steam version in any way that would break modding?

There's a mod spotlight coming, so mods should work.

Which should I use for CoP, they both look very good:

CoP Complete or Misery?

I would say to try the Misery mod for call of Pripyat, but.. Wait untill 2.1 is released. I found 2.0 to be quite buggy (this was when it first came out, mind you. I dont know if they have released any mini patches since then, but I'll just wait for 2.1)

It's still worth a try though I have to add, bugs an all.

I was about to suggest some mods that seem to have vanished... might have to put them on my dropbox as i cannot find you a link for freeplay or ultimate mod.

oh, and of course Priboi Story (which is basically a total conversion for SoC - giving it a similar plot to CoP, yet it predates CoP).
http://www.dezowave.com/

One thing though - just noticed another guys post stating that SoC is version 1.0006 - meaning a lot of mods wont work with it at all!

For SoC and Clear Sky I would recommend the "Complete" mod. Just don´t use it for CoP, since this version is not from the authors of the first two versions and it is a complete mess.

For CoP I recommend "Sigerous", "I Work Alone" or "Misery", although for Misery you need to have a masochistic streak.

And be aware that at least Sigerous contains the brilliant "Atmosfear 3" and "Absolute Nature 3", which WILL bring your rig to its knees, no matter how powerful it is!

What the major difference between LURK and Complete to a player new to the series?