The "white suit" era---that's what they are pictured in on the original U.K. pressing (there was no U.S. release at the time) of the "Live In London" LP (1968). After they signed to Reprise in 1970 they put out a few good albums (Sunflower, Surf's Up, Holland, So Tough), then came the horrid "Brian is Back" fiasco with the poor "15 Big Ones" album, an exercise in nostalgia, right up Mike Love's alley. Their final good album was "Love You" (1977), after which Brian again dropped out. That was the end of The Beach Boys for me.
I saw Brian on his first solo tour, and it was the most heartbreaking, sad, depressing, and pathetic spectacles I've ever witnessed. He obviously has brain damage from, I assume, his years of self-medication. I vowed to never again put myself through that, so avoided seeing a live performance of the "Smile" album, much as I would have loved to. I have so far avoided seeing the Love and Mercy movie, though I guess I eventually will. Rock n' Roll's most tragic figure, and it's most genius.