In my opinion (and my friends and family), Charlie was a very hard character to like, firstly she dumps Joey for Ross and then to dump Ross for her ex (Benjamin Hobart played by Greg Kinnear) and she hated Rachel aswell. Finally she is gone.
It was very funny watching who got Phoebe's ugly painting out of Monica and Rachel, as Phoebe was making room for Mike to move in. In the end Phoebe made another one even worse. So they each got one.