Pripyat is the more polished game mechanically. SoC has the best story. They're more or less equal in atmosphere.
I bounced off SoC the first time I played it, but after I finished Pripyat the first time I gave SoC another go and I got totally immersed.
It's hard to recommend one over the other. They're both great.
S.T.A.L.K.E.R.
All three base games. So many mods.
The zone feels vast, lived in, dangerous.
The ai is dynamic, moving through an area once you mind find a group of friendlies engaged in a firefight with a powerful psychic mutant, and other time find an eerily peaceful vista.
It's not a power fantasy. On harder difficulties you're always on edge when you're exploring even with end game gear. A single bullet from a sniper or a random pack of wild dogs can easily end your run.
Highly recommended of you've never experienced it before.
Try it.
On USB with the basic driver specifically, modern HP printers will let you use the device for exactly 10 print jobs before it locks all functionality and demands that the unit be connected to the network and an HP account registered.
Do not buy them. Find a brother instead.