MGS3. Story and gameplay.
I can understand people saying that MGSV has better gameplay, but I disagree. Kaz and Ocelot can't stop talking in your ear all the freakin' time. It's more than annoying. You have to stop upgrading your stuff very early on for gameplay to stay fun because once you upgrade some stuff it just becomes retarded easy. And buddies, while a cool addition to the game, make that problem even worse. It's not a very well balanced game. The fact that you're constantly on the lookout for best soldiers means that you're not playing the game as much as you're focusing on extracting personnel with good stats. And then most of them can die anyway because shitty game design and story are shitty. And you have to keep collecting resources so you can pay for your deployment in the field. Jesus fuckin' Christ.
But my biggest gripe of all is that weapon selection is limited. Weapon modding is cool, but why can't I bring two pistols with me? Why do I have to select just one assault weapon and one sniper rifle? Or whatever the hell else I like? Why do I have to collect so many resources all the time? It feels like playing two separate games, none of which are very fun in the end because of it. The motherbase is a useless addition to the game as well. There are so many things in this game that exist only because the entirety of MGS V was designed with microtransactions in mind and it shows.
People wanted to know how a fully priced game would look like if it tried to milk people for microtransactions, and MGSV is that game. Motherbase exists because KONAMI wanted to implement microtransactions. They did that with FOB bases and what is basically a protection racket that you pay Konami to keep your base safe. All of that bullshit could have been avoided if there simply wasn't a motherbase to begin with. No motherbase, no FOB's and no microtransactions. Without that there would have been no need to collect boring resources all the time, and the game would actually feel like a real stealth game instead of like some stupid fuckin' grindfest.
Or you know, maybe you can have a motherbase that is actually fun to play with if it was designed to be fun. But it wasn't.