I grew up with the show as a kid and it was so good, and well scripted and really smart. As a 12 year old kid at the time, I loved how it didn't talk down to children and the tv show will definitely be something I buy on DVD for my own children when I'm older. Even for adults, I definitely recommend buying the show on DVD and watching it with your kids! I'm 19 now and I still think it has so much to offer all ages!
As for the movie. It's terrible. It might be able to hold your kids attention, but not only does it take all the creativity and character of the original series and butcher it, the acting is terrible, the characters are boring, though some of the effects are good, most are pretty laughable. It's just not a fair representation of the original series. If I could rate zero stars, I would.
Please, any parents who are planning on buying this for their children to watch, spend a couple more pounds to buy series one of the TV series and I promise you will not be disappointed. It's a wonderful, funny, smart and sometimes even moving story.