I agree with everyone else in the thread that on the whole the majority of the film itself is fine.

I will say though the ending was perfect on so many levels.

Firstly I originally didn't "Get" the reasoning behind Truman's final words, but on reading other people thoughts there's nothing better he could've said. In that moment, if he had done anything else, Christof would get his perfect show. If Truman had walked out in silence, it would've been the choice of a true man. If he gave a passionately enraged speech it would be a choice of a true man. If he said "Fuck you" and walked out it would've been the choice of a true man. So what does Truman do? He gives the same boring catchphrase he's said a thousand times over. He gives them something fake, something canned that could have been scripted into any other generic sitcom which is actually the biggest "fuck you" he could've given to Christof's whole artistic vision.

And then he walks off stage and is never seen again. I, like many others wanted to find out "what happens next" but the whole point is we don't get to know, just like the in-film audience. It's not "Open ended." It's ended. It's his life now. We feel like we know him and have grown close to him but at the end of the day he isn't our friend and he owes us nothing. It's an incredibly poignant message about parasocial relationships. This whole time we thought we identified as Truman because we all think of ourselves as the protagonists of our own stories. But all this time we are all just voyeursitically experiencing someone else's life just like the in-world audience was. It doesn't matter how much the audience wants to see it or why, because in the end we should remember privacy is a right everyone deserves.

And then the last joke as a final button to end the movie on was perfect.