Shadow of ChernobylEdit
My favorite gun has always been in the 5.45 variety - namely Strelok's AK - but a close second is likely the LR-300.
I have sided with Freedom, even if I don't engage with Duty. They're nicer, despite them being sharper in SoC more than they were in 2011; they have a larger base than Duty, and certainly allow strangers in opposed to Duty before X16.
A second favorite faction to Freedom is the Monolith. I just like them, and soon, I'll try making a mod with them being friends, since they are just... cool.
My least favorite faction is - well, Duty.
I find it a misconception that Freedom wants anarchy; I believe they want to spread the information of the Zone to the world, which I don't believe is anarchy.
I know that the mod I will play the most, ever, will be Lost Alpha. When the new Stalker Rebalanced comes out, that'll be a close second, since I've always found that it's an enjoyable mod.
By far, SoC is my favorite Stalker game, but CoP is close in a different way; SoC offers so much what I call forward-story; Clear Sky's story wouldn't make much sense without SoC, but it would also be interesting to play CS > SoC > CoP to get the timeline perfect.
My favorite armor is the Stalker Suit, but, if I could, I would have the Ecologist's variant of it (the cut one, but the texture is still in the game).