The Little Mermaid
I must admit that I haven't watched a great number of films from the eighties, and those that I have, I either found forgettable, or wasn't that in to. There were some that I enjoyed the first time that I saw them (The Naked Gun), but now don't think are that good anymore.
The one place I know I can confidently return to is Disney, and The Little Mermaid was the first in a line of highly successful films that followed for the the next decade. It was near the end of the eighties, and a film I have always enjoyed watching.