- The Torch playing tricks on the Thing.
- The Thing wandering around in a coat and hat, wrecking a car, having trouble picking things up or pressing buttons, and eating a huge stack of pancakes.
- A fight between Reed and the Thing with Reed wrapping himself around Ben.
- The Thing being cured but reverting in order to save his teammates.
- The Baxter Building with Willie Lumpkin the mailman (Stan Lee in a cameo).
- The Torch making the "4" symbol.
But these are small things. It's the big things they got wrong.
Reed was miscast. I never accepted Ioan Gruffudd. Reed may had been an absent-minded-professor but he was never indecisive.
The rest of the team was ok. I cannot accept Jessica Alba as a geneticist but this was mainly an excuse to have her on the space station.
Doctor Doom just didn't work as a corporate leader gone crazy. In the comics he was ruler of his own (small) country with robot armies at his command. He was an ambiguous character - protecting his people while oppressing them.
In the comics, the FF's origin was mainly background. Spider-Man and Batman were motivated by their origins. The FF didn't need a reason to fight crime. They got their powers and decided that they should use them to help people.
In the movie, they got their powers and did nothing. They hid in Reed's lab. They tested their powers. The only time they used them in public was, first to clean up after a traffic accident Ben caused, then to defend themselves against Dr. Doom.
How should the movie have been made? I would have started it with a quick origin, possibly an attempt to win the X-prize. The FF would have their powers within the first 10-15 minutes.
Cut to credits showing newspaper articles about the FF.
Pick up with the scene in the bar with the Thing meeting Alicia. End it with Reed summoning the FF. Latvertia is threatening its neighbors or something similar. The State Department is asking the FF to take care of it unofficially. In the briefing it is mentioned that Reed has a history with Latvertia's ruler.
We take it from there - frightened villagers, robot army, a fight with Doom and the weapons built into his armor.