I don't think there's any such thing as a "perfect" game, but The Last of Us comes pretty damn close to my definition. The story, acting, motion capture, blend of gameplay elements, graphics and sound all mix to create an incredibly enjoyable overall experience. The single player and multiplayer are well-balanced individual components that serve to enhance and inform eachother without relying on or overriding the other.
Even the premise, which can loosely be described as "a zombie apocalypse" game, manages to avoid feeling tired and cliche by not only adding a little twist to the "infection" and its result, but creates an interesting world in which it exists. The primary plot device is a little predictable, but the journey more than makes up for it.
In fact if I'm sitting down to list pros and cons, the only cons I can come up with are, ultimately, nitpicks. Those instances where the importance of gameplay mechanics runs headlong into the overall realism that the game is striving to create, and produces a little speedbump. They aren't the kind of thing that detract from the game, but they're impossible to not notice.
I would classify The Last of Us as 'survival horror' and so in a lot of instances, you're best served by running from a fight, or sneaking past it. And sneaking is serious business against fast and vicious enemies, some of whom see via echolocation. You need to be patient, and move slowly to navigate past a minefield of deadly runners and clickers. So then it's a little jarring when, in the midst of your careful maneuvers, your AI partner is running around, knocking shit over, and generally making no attempt to avoid being seen. And the enemies do nothing.
Now obviously it had to be this way... you cannot be held responsible for the actions of a character you cannot control. If the jig was up everytime the pathing glitched out and Ellie ran right in front of an enemy when moving between cover, even though you were being super sneaky, it would be incredibly frustrating. Gameplay has to be priority number one here. So while moving slightly too quickly in the presence of a clicker will bring the wrath of hell down for you, Ellie is free to dance around, whistling and swearing and playing the trombone and they'll happily ignore it.
Your companion(s) often do a good enough job attempting to mimick your stealthy approaches, but you'll be rolling your eyes when they don't.
The characters here steal the show, without a doubt. Not that we would expect any less from the studio that brought us Uncharted, but the dynamic between Joel and Ellie is such a different experience than what we got with Nathan Drake. Apart from cutscenes and certain sections, you spend a lot of the Uncharted series alone, with only Drake's quips for company in your travels.
Joel, on the other hand, is rarely alone. From the gripping opening scene, to the calm exploratory moments between enemy areas, he's got someone there with him, and they're conversing and interacting. He's with nobody more than he's with Ellie, and the reward for that is that you not only see that friendship blossom, it feels genuine. You start to feel viciously protective of her in dangerous situations. I can't be the only person who is extra careful moving the pallet while she's on it.
Ellie's voice actress nails the Ellen Page thing the developer was very clearly going for, while Joel is far more gruff and weathered than Nathan Drake ever was. He's surly and bitter, and worn down (with good reason), but there's a southern charm that you can see under the surface from the start, and becomes more familiar as Ellie gets past his defenses. It's a fantastic pair of characters that you'll be happy you got to know.
I haven't played much multiplayer, but I did immediately find it more natural and plausible than the multiplayer the later Uncharted games had tacked on. Set in the same world, you take on the role of a random shmuck from one of two factions, and you have a little band of survivors. When you play a multiplayer match, your sole job is not to slaughter your opponent, but to collect resources which then feed and supply your survivors.
The matches can be intense, and rely on a lot of the stealthy and carefully executed mechanics of the primary game. It's not hectic run and gun. Multiplayer definitely benefits from communication and teamwork, which can be tough to find, but you're best served just by sticking close to at least one other person so you can help eachother out.
It's an interesting set-up to the whole approach, and one that I feel contributes to the world the single player campaign creates. You won't buy The Last of Us just for the online component, but you'll probably be happy it's there once you're done with the campaign.
Like Uncharted, I think it's a sin if you own a Playstation 3 and don't buy The Last of Us. This is one of those console-exclusive gems that do exactly what exclusives are intended to do: give you a reason to own the system.