1. InFamous isn't that great imo. It's a solid game, but after the novelty wears off, it becomes extremely repetitive. Mid-way through the game, I noticed I had to force myself to sit through gameplay sessions any longer than 15 minutes.
2. I don't think I need to explain why I like God of War. The series has been accepted well by critics and gamers and their reasons are well known. The appeal of God of War isn't much of a secret.
As for Killzone, I didn't really enjoy KZ3 but I thought KZ2 was great. I didn't really care much for the single-player in either game. The multiplayer was what I loved and KZ2 satisfied me the most there. The hit detection, spawn system, health system, aiming system, weapons, and movement all make the core of Killzone 2 much more than most other shooters imo.
3. I really don't care for reviews. If the games are enjoyable and make good profit, then I'm fine. Reviews have been pretty crazy lately anyway.