Raiders is just one of those films that has so many great scenes and sequences to pick from. Some just following on from the previous one.
For as long as I can remember the truck chase shades it for me, really good action with a score to match. But as I've got older I think the map room scene is one that stands out too but for different reasons. It reminds me of something from a biblical epic in its look and score.
The anticipation of Indy finding the Well of the Souls makes it a tense scene too, because as a viewer you are intrigued to see what this place looks like. Also its like the macguffin has been found early in the film because we know thats supposedly where the ark is too.
But I think the thing that sets this scene aside is John Williams music, which as previously mentioned harks back to the 1950's Hollywood biblical epics and as its builds to a crescendo its just perfect.