I wasn't entirely sure what to expect of Madagascar. I saw the trailer a while back - an animated film about animals in the Central Park Zoo escaping - and thought, "Hmm. That will either be really cute or it will really suck". Fortunately, as it turns out, it wasn't a bad movie. Not as good as Shrek, maybe, or even Finding Nemo, but not nearly as bad as, say, sitting through a showing of Platform. Part of my prejudice against the film going in was the stars voicing it - Ben Stiller, David Schwimmer, Jada Pinkett Smith and Chris Rock. Not that I have anything in particular against any of these actors (well, except perhaps for Rock, whom I tend to find annoying).
It's this trend toward animated films having to have big-name stars paid big-name money for children's movies. Used to be, actors would voice kiddy films for scale, just to be nice, and to have their name and voice on something their own kids would watch. These days, thanks to Robin Williams and that damn Genie from Aladdin, every star wants to be in animated films, and they all want big money to boot.