Wow it seems like some of you really rushed through it, TLOU isn't meant to be played that way but oh well... it took me almost 4 hours, exploring every corner and just enjoying and looking at the environments, was totally worth it.
just like chaystic, i didn't count the time it took but i'm pretty sure it was close to 4 hours on difficult. i explored almost everything and i still didn't find all the collectables and optional discussions.
GREAT if you ask me!
EDIT: actually my save file shows that i played 2hours and 40 minutes, but i think it's wrong, it felt way longer... maybe the counter didn't include the cutscenes? anyway it felt longer than that.