Fallout: New Vegas vs S.T.A.L.K.E.R.: Clear Sky
Fallout: New Vegas
Fallout: New Vegas is what many hardcore fans of the popular game franchise called a "spin-off" but even so, the game is incredibly well-done in terms of its gameplay and graphics. You'll get to experience a whole new "world" (the map of post-apocalyptic Vegas... a.k.a. New Vegas) filled with plenty of hidden secrets and interesting quests to discover. There is also a more intriguing connection between the characters in this game, allowing for an epic power struggle between factions to realistically play out... with some nudging of your own, of course.The game even boasts of a new features like a companion wheel so you can order your companion around in a smoother manner, as well as a weapon configuration system that may not be as in-depth as in Fallout 4 but it definitely paves the way to the incredible weapon crafting/customization system that the game uses today.
The most unfortunate part about this game though is that it's riddled with quite a lot of glitches - none of which are truly gamebreaking but they can be rather immersion-breaking. Nonetheless, despite being kind of like the black sheep in the family, Fallout: New Vegas is still a fantastic open world RPG with one of the creepiest Fallout DLCs (IMHO).
S.T.A.L.K.E.R.: Clear Sky
S.T.A.L.K.E.R.: Clear Sky is the second installment in the S.T.A.L.K.E.R. series and yet is the prequel to the original game. In this game, a group of stalkers have unwittingly triggered an explosion of anomalies when they ventured into the heart of the exclusion zone - the Chernobyl Nuclear Power Plant itself, turning the entire zone into an unstable mess that continues to quake with anomaly outbursts. Stalker factions have also erupted, further adding to the overall chaos of the region.S.T.A.L.K.E.R.: Clear Sky is essentially similar to the previous game, though it does have some significant improvements. For instance, the game is a lot more stable, which is ironic considering that all the storyline in this game talks about is how unstable the zone is. The weapons and armor in the game work better than in the original since they can, finally, be repaired. Artifacts are harder to find here but is a lot more rewarding and well, generally the overall setting feel a lot more realistic.
This is definitely a nicer game to play than its first game, but it's not really comparable to the third game of course. However, if you love the S.T.A.L.K.E.R., you might still want to consider buying all three games via its Steam bundle.