I have the philosophy that kids are more apt to become lifelong enthusiastic readers if they are allowed to read what they most enjoy reading.
Kids are no different.
If the reading is always tough for them they are much less likely to want to read for fun. I feel one of my main goals as a school librarian is to foster in my students a love for reading. It would be great if all kids read the classics. I realize, however, if Goosebumps, Nancy Drew, Hardy Boys, Babysitter Club books, and comics are what they most want to read they should be encouraged to do that. If you can get them hooked on books, don't worry so much what they are reading because eventually they will start to branch out into better literature with gentle guidance.