We all know that the Beatles dominated the rock music scene during the 60's, but they also had top competitors during those years. These are artists who in my opinion approached or equaled the level of the Fab Four each year from 1965 to 1969; I took into account factors such as innovation, quality and quantity of released material.
1965: The Byrds. This band defined folk rock with their excellent debut album:
Mr. Tambourine Man, which was a big influence for
Rubber Soul. They also released a second album the same year with a similar sound:
Turn! Turn! Turn!.
1966: The Beach Boys. This was a marvelous year for rock music, but only
Pet Sounds could compete with the magnificence of
Revolver.
1967: The Doors. A difficult election because of all the great music that appeared that year, but the Doors released (in my opinion) their two best albums of their career: their self-titled debut and
Strange Days.
1968: The Rolling Stones. After following the Beatles the previous years, with good but not as great imitations, the Stones came back to their origins and recorded a sequence of wonderful albums, starting this year with
Beggars Banquet (plus the single "Jumping Jack Flash").
1969: The Who. This year saw the release of the definitive rock opera:
Tommy. I even think that the B-side of
Abbey Road was pretty much influenced by that album.