SoC:
+Best story (muh search for the Russian soul).
+Longest.
+Spoopiest.
+You are Strelok.
+All other entries are really just standalone expansions/mods, SoC is the OG.
+Running straight into the Chernobyl NPP as a blowout started while shaking off the military/monolith was absolutely fucking metal.
-Horrible release bugs. Vanilla version playable within weeks of NA release, as far as I know is bug-free on current version.
-Lack of repair or upgrade options for weapons/armor.
-Vanilla has cheeki graphics.
CS:
+Dat shootout in Limansk.
+The zone is alive and you can see how it has changed between CS and SoC in DarkValley/Cordon/etc.
+Can repair weapons/armor, upgrades too
-Upgrades turn all guns into RNG bullet hoses or sniper rifles.
-Arguably buggier on release than SoC. Much more demanding on hardware for only moderate graphics improvement.
-Faction wars buggier than roadside turd.
+Dat fucking shootout in Limansk, holy shit. Felt like the best parts of cowadooty as re-imagined by slavaboos.
CoP:
+You can actually play through the game on version 1.0
+Lots of care and thought went into level design. Rewards exploration of every shrub, hole in the wall, and terrifying earth mover.
+Weapon upgrades/Armor mods allow lots of customization and freedom. I love how the toolkits took for-fucking-ever for me to find (refused to use walkthroughs on first playthrough) and were also the most exciting items in the game to finally get.
-Physically the smallest game; packs about the same amount of "content" into only three areas basically.
-You are not Strelok.
+Has Strelok in the game.
-Even though you belong to the most hated faction in the zone (military), no stalkers can find out until you shpill the beans yourself on arrival in Pripyat what if getting caught is part of my plan??. Even after you dox yourself and return to Jupiter and Zaton, no one turns hostile (Zulu merely becomes tsundere until you rescue him from his rebound gangbang with snorks).
-The shootout at the end was underwhelming tbh fam
CoP is the best "game".
SoC is the best "holy shit what is this" new experience.
CS is mod-tier quality but viewed in that light it's the best stalker "mod".
Lost Alpha was shit on release. May have to play it again, the devs might have patched it so you can steer vehicles above 10 km/hr.