Angels and Demons was much better than the Da Vinci Code. And I could draw the Illuminati symbols when I got bored xD
There's not really anything inappropriate in either, at least not until the last chapter when Langdon gets (-insert main female character here-) in bed. He doesn't go into detail though, and he does it at the end of all of his books anyways.
If you're worried about the different ways that the cardinals die, there's a different story for you. They aren't 'inappropriate' per say, but they are a bit harsh.