Variety of Genres

The NCTE believes it is important that students read a variety of different genres.  When my sister was in the fifth grade, she was working her way through the Goosebumps series.  After a while her teacher told her she was no longer allowed to read Goosebumps, she had to choose something else.  Suddenly, something she found fun and exciting (reading) was a chore to be completed for twenty minutes each day.  How do you make sure a child is varying genres without diminishing a love for reading?