From what I hear in Hollywood people tend to be the exact opposite in off screen then they are on screen. For example Michael Landon played the good ol' hard working honest father on Little House On The Prairie and an angel on Highway To Heaven. However in real life he had three bitter divorces, liked to sleep with lots of women, drink heavily and smoke more than 4 packs per day.
on the flip side , the guy i think mocks hollywood better than any other is clooney .. can laugh at himself and seems like a guy you'd want as a close friend.