When I was young I listened a lot to the music of Mike Oldfield but at some point, less so. Recently I started again and I still love the music.
Tubular Bells (1973) is of course the original work of art, but for me the two masterpieces remain Ommadawn (1975) and the immensely different Amarok (1990). The Songs of Distant Earth (1994) is also very good.