Metal gear solid 4 resonates very highly to me, and the reason is that it does a very good job in its story.
The issue i have isn't story related for the most part, its the bosses thrown at you, and a few parts of the script.
The bosses are mostly not as memorable as metal gear solid 1-3, and exist solely to live off past nostalgia of those games.They even throw in a metal gear rex battle which i actually really had a lot of fun with.I think they even tried to push raiden a bit too much by making him showboat to make up for metal gear solid 2.
I have a problem as well with naomi and i won't spoil what happens, but i will just say that i have never been all that fond of her.
The guy who sells weapons who has that monkey on his shoulder is likeable enough and im glad ocelot is in it, and vamp.Ocelot and vamp are 2 major guys in mgs2 who i think are very solid characters and bosses
Gameplay wise i have a few complaints as well:
I think the game kinda encouraged you more to be going out guns blazing.Seriously, you can load up on an infinite amount of guns, and snake can carry them.Some of them are mostly the same, and they took out eating and bandaging from mgs3 for some reason.I liked tranquilizing animals and eating them later, i thought it was neat.I also liked the idea of hiding a snake in your pack and throwing it at a guard.
The new tech you get is good, but i kinda wish also you could get more chaff grenades.By the end of the game you really need chaff grenades.Without them its frustrating to go for a silent run.
Overall i think mgs4 is solid and beats mgs1 and 2, but doesn't quite reach mgs 3's level.