The Beatles were for me the first introduction to being obsessive about music as a listener (and later as a musician, and I mean this in the best of ways. I spent many hours from around grade 4 and on listening to the amazing breadth of their work. Started from the "White Album," and made my way slowly through the catalog. Thanks for the great music!!
The Beatles always impressed me with the diversity of their songwriting. They're probably the first group I acknowledged as experimenting with and ultimately shaping several styles of popular music. More than any particular song I've always admired The Beatles for the confidence they had in their own curiosity.