I think my favourite part was Indy surviving a nuclear explosion by getting into a lead-lined refrigerator. Not so much that the fridge part, but more that he survived the fridge being blasted into the air by the explosion and crashing into the desert. I think that made me LOL more than anything else in the film. Science in the Indiana Jones movies is rather like science in Doctor Who: it requires complete suspension of disbelief. And should be spelled 'skience' for that reason.
Um, so the crystal skulls idea was cool, but Spielberg seems to have a major thing for tall skinny aliens with big eyes. It looks like he just took the character design for them from 'A.I.', even that whole element of being psychic. That's a minor quibble though, because pretty much everything worked for me.
And is it me, or is Alan Dale in, like, everything? He's on Aussie tv at the moment in Lost, Ugly Betty and this stupid sounding local drama Sea Patrol. And before that, there was JAG, NCIS and The OC. I think it all comes to his voice. It has that booming quality that works when you're playing authority figures like US army generals and CEOs.
All in all I loved it, but I think that Raiders is still my favourite out of the four. I totally thought they were going to do something with it when they showed the busted warehouse container with the Ark of the Covenant in it.