Circa 1968, The Byrds Greatest Hits was one of my first albums; it helped shape a life-long enjoyment of jangly folk-rock (and later indie pop).
More recently, Beth Orton's Trailer Park and Sugaring Season, along with Molly Burch's First Flower, helped introduce me in retirement to a newer generation of singer-songwriters.
The Celtic Music of Brittany by the Celtic Angels pushed a bit on my understanding of what Celtic music can be (beyond old school Irish styles).