[gypsysoul]

For various reasons I've have lots of dealings with celebrities, everyone from Z listers to the big A listers.
Generally speaking, the bigger the star, the nicer they are. Two notable exceptions are Jennifer Aniston and kylie Minogue - their nice girl images seem to be purely for the cameras and when there are 'important' people around.
(Angelina Jolie, however, is fantastic, one of the nicest celebrities I have met).

The worst attack of 'don't you know who I am' seems to strike the 'models/actresses' whose sole claim to fame is that they have slept with a famous man.
I did some voluntary work for a charity for a couple of years and we regularly invited celebrities to our events. The big names were almost always gracious and generous.
The 'model/actress' types on the other hand would put forward an absurd list of demands before they committed to attending. Though they all made big play in the media about their involvement with charity, some of them even asked us for a 'shopping allowance' if we wanted them to turn up at the event.
They had such an inflated opinion of their fame and 'talent' it was embarrassing.