I saw it too and liked it overall.
However, it was not my favorite of the four; my favorite is still Raiders of the Lost Ark. I think the Crystal Skull story was a little too convoluted; much could have been taken out that did not contribute to furthering the story.
The movie also included a few teasers that make me wonder (and hope) that more Indiana Jones movies might be produced in the future. For example, Indiana Jones seemed to know quite a lot about the Crystal Skull, as if he had been the one who originally found it. Perhaps there would be another movie about that adventure. How many other adventures has he had without sharing them with movie-goers? I am sure there are still many more movies that could be made. Personally, it doesn't matter to me whether they include Harrison Ford, George Lucas, or Stephen Spielberg; I just like adventure movies about ancient mysteries and artifacts.