The opening scene featuring a T-Rex hunting hadrosaurs next to the ocean before being killed itself by a meg. I know it's not accurate as Megs didn't exist in the Cretaceous period but it's a great scene.
The meg hunting a surfer (this was ripped off by Fallen Kingdom!)
The meg hunting whales.
The chaos at the end where the Meg is attacking the huge group of boats, ships and helicopters that have assembled to take pictures of the Meg.
The ending where Jonas get swallowed by the meg whole and has to stab it's heart and fight his way out (sounds cheesy but the scene in the books is awesome.)