I agree with a number of previous posters here on the order:

Raiders of the Lost Ark (10/10)
The Last Crusade (9/10)
The Temple of Doom (7/10)
The Kingdom of the Crystal Skull (6/10)

In my opinion, Raiders is one of the most perfect films made for its time. The plot, pacing, music, casting, acting, screenplay, special effects… Everything just works beautifully, resulting in film I never grow tired of (like Empire).

Doom has its moments, but a little too much slapstick in places given how dark it is elsewhere. The tone feels inconsistent as others have pointed out. Kate Capshaw’s incessant screaming can also be quite annoying.

Crusade is a rollercoaster of a film, almost up to the level of Raiders in my book. It successfully recreates all the excitement and wonder of the original, without including the annoying features of Doom. And Alison Doody… My oh my…

I’ve only seen Skull once (at the cinema) and my rather vague recollection is “meh”.