Honesty the gameplay is phenomenal, and the extra content you unlock at the end is also very good, but the storyline is completely unforgivable. SPOILERS:
They kill off the most loved character Joel at the very start of the game, then make you play as his killer Abby for the majority of the game. They try to make you feel sympathy for her, but I can't forgive her. And in the end, when Ellie is going to kill Abby and get revenge, she gets off Scott free. Ellie even ends up SAVING abby from torture.
Tl;dr: gameplay, great. Storyline, abysmal.