Any mod recommendations? There are usually some "must have" mods for games with a vibrant enough modding community. I'm leaning towards grabbing it!
The Stalker Complete 2009 linked by ne_zavarj is a must have for me for SoC. It's like a graphics update and does a lot for a game like this that oozes atmosphere. I also throw in the nature mod spring edition to color up the grass/trees a little more.
A lot are personal flavor and I can only recommend ones I have now, as I can't remember all the past ones. The Greedy trader repair mod, less bad nightvision, random stashes, and I have one total conversion Priboi story but i haven't really played it a lot.
For CoP, I have only been running Atmosfear and the absolute texture packs from Cromm Cruac .
There is just so many for all the games in the series. Even twice as many if you can understand Russian and use those mods as well 
Oh Yea, that is a super sick price for those two games. If I didn't already have them....
and please please Stardock go after the publisher of Clear Sky, I'd love to have all three on Impulse.