Raiders of the Lost Ark
Indiana Jones & the Last Crusade
Indiana Jones & the Temple of Doom (just barely beaten by Last Crusade, I just put Crusade above it because it has less of the obnoxious time expanding editing and less bad guys with distractingly terrible aim. I mean, come on, one of those arrows HAD to have hit Indy when he was climbing the bridge, they shot like 3 volleys!! Other than that I still love it though)
Crystal Skull failed in my opinion because it lacked any real grit. In fact, I don't think Indy actually kills anyone on screen (correct me if I'm wrong). It looked like a cartoon and the end with the aliens made no sense and was hysterical. Weird stuff happened with the Ark and the Grail, but it made sense: The ark killed Belock because he was evil and the wrath of God killed him, and the Grail killed Donovan because, "for the unrighteous the cup of life holds everlasting damnation". Why did the aliens take away the lady and all the Russians but leave the good guys? Why did the aliens combine themselves together? I could've enjoyed an alien artifact if the item was simply that, an artifact, and something that they had to track down from the past, I didn't even mind the whole brain washing thing, it just got way to silly and confusing at the end with putting the alien skull back on the body. I liked the villains, I liked the alien skull, I liked the 50's era, and I didn't mind Harrison Ford's age, it's just the execution where everything failed. I honestly didn't mind it until they got to the jungle, the first 45 minutes or so were actually very promising.