Listen, the problem was that raiders set the bar so high that many family adventure films never met!! There really isnt a bad inday film, hence why they are loved in the same breath as starwars back to the future etc.
Raiders - Classic
Doom - in my opinion most of the memorable indy scenes are in this movie, and i dont recall any other indy that he has "no time for love doctor jones"
Crusade - My personal favourite, plenty of humor, great casting and probably the best artifact!! Full Marks
Skull - the only dark cloud for me is the swinging in the trees with the monkeys. The rest was a perfectly fun saturday afternoon movie, with the 50's tone set perfectly!! It had also lost two great characters in denholm and connery, but introdeced mutt who was perfectly fine, i just think no one likes shia lebeuf, cant see the problem with the guy to be honest!!
Anyway i would not really welcome a 5th installment as i dont think it would be an indiana movie, as proven in "skull" indy sat out of most of the action sequences and left them to Mutt. and i just feel that they would be making a "Mutt Jones and problems with puberty"!! Rather than a indiana jones and the lost city of atlantis etc.
Anyway Indiana Jones movies are ace, simples!!!