The Secret of NIMH (1982)

  I cannot tell you how many times I watched this as a kid.  When I was old enough, I remember tracking down the books through the school library and being very disappointed because they were not nearly as mystical as the movie.

Mrs. Brisby (Elizabeth Hartman) is a widowed field mouse living with her four children in a cinder block in Farmer Fitzgibbons' field.  She knows they have to move before plowing time but her youngest son has pneumonia and will likely die if exposed to the elements.  In desperation, she turns to the rats of NIMH, a group of hyper-intelligent escaped medical experiments, for help and runs smack dab into the middle of a coup as Jenner (Paul Shenar) plots against the rats' leader, Nicodemus (Derek Jacobi).

The animation is not as crisp or clean as modern movies but this film holds up very well despite that. You are most likely in the age group to feel nostalgic about this, rather than coming to it for the first time but there are always holdouts.  If you had not seen this, you missed out on something vital as a child.  I don't know if you could capture that feeling again as an adult but it's not too late to show it to the newest generation.  The world could always use more people raised on The Secret of NIMH.