Yeah, Elephant Graveyard for sure. For the reasons mentioned in the first post of this thread

The Elephant Graveyard was also a much longer sequence and felt more like something that was a significant part of the film, not
just a plot device. The crocodile chase... was more something to form a friendly bond between Kiara and Kovu. Which of course also is important, but for scene as such, Elephant Graveyard was tons better.