I've beaten TLoU on my 80GB Phat and had no crashes at all, but I did encounter quite a few texture problems from the middle of the game to the end. Texture on models sometimes would not load up, so I had to exit to the title screen and reload my save. There was one point where half the sky was a giant black box.
I've also encountered a lot of low res textures in the last half of the game, too. A lot of signs were unreadable, items that I picked up, such as maps, were just blobs of color on a paper, and some environment textures on things like logs were really horrible. I reloaded my game several times and it might fix some of the low res textures, but then others would pop up.