The Temple of Doom
First, it's the only one of the lot to actually feature that signature, splashy comic-booky title card. (The other two use fairly understated text to reveal their titles.)
Opens with a fucking musical number. That shifts into a tense stand-off. That shifts into an action/chase scene. And then we're up in the skies for a brief respite before another huge action sequence!
In Raiders, we've got several parties looking for the Ark.
In Crusade, we've got several parties looking for the Grail.
In Temple, Indy's party is alone in their mission. And freeing enslaved kids is much more of a clear "win" than what either Raiders or Crusade have to offer. (In fact, the endings of both Raiders and Crusade rely on Indy surrendering the object he's looking for.)
I was too young to appreciate Raiders when my folks dragged me to it in theaters; it was too mature for me to fully appreciate. Good and evil is a lot more clear in Temple. The bad guy is clearly evil.
The bug scene is wayyy more intense than the snakes in Raiders or the rats in Crusade.
Big mine-cart chase sequence?! Amazing.
And, of course, Short-Round was the perfect Indy sidekick.
People complain that Temple's too dark. I argue it's clearly the most kid-friendly of the lot. And it's way more focused than Crusade.
There, I said it.