I have yet to play Bioshock Infinite yet - will get that soon - but unless that REALLY impresses me, The Last of Us is easily the GOTY. Easily. It is the best game I have played this generation, and that is saying a lot. As far as the ending goes, there is nothing wrong with it save that they are leaving it open for a sequel if it does well (which it most definitely is). It really drives home how Joel has changed and now wants to cope with what happened at the start of the game.
As far as the friendly characters sometimes doing silly stuff, really, it wasn't that bad at all. For the most part, they are perfectly fine and did whatever was necessary to help me out. For a game with such intelligent enemy AI, multiple paths and methods of approaching a situation, the friendly AI is great. The details in this game are simply incredible. If anyone had any doubt about Sony having the better exclusives after Journey/Shadow of the Colossus/Metal Gear Solid 4/Uncharted 2 (games considered true masterpieces), The Last of Us really hammers it home.