The Beach Boys' calling card could be one of many songs recorded in their early years: "California Girls," "I Get Around," "Be True to Your School," or "Surfin' U.S.A." But "Good Vibrations" is considered Brian Wilson's calling card.
For starters, the song reflected his maturation as a songwriter and producer. By the time he began "Good Vibrations," he'd retired from the road and was no longer part of the touring Beach Boys. Instead, he wanted to concentrate on writing and producing. He also wanted to move beyond the instrumental and arrangement simplicities of the band's early work.
Second, Wilson had to produce this song over the objections of some of the band's other members. They were less enthusiastic than he about changing the band's style and developing a more studio-intensive sound.
Third, Wilson embarked on the recording process with the intention of making the song "the summation" of his musical vision. An LSD trip had inspired him to make "Good Vibrations," which he had written some weeks earlier, "the summation of my musical vision, a harmonic convergence of imagination and talent, production values and craft, songwriting and spirituality." (Source, 145)
Finally, by the time Wilson finished recording the song, he felt he'd succeeded in producing the masterpiece he intended. It left him with a "feeling of power, it was a rush. A feeling of exultation. Artistic beauty. It was everything." (Source)
Wilson wanted to make the Beach Boys' entire next album, SMiLE, in the same way that he had made "Good Vibrations," but drug abuse and mental instability forced him to put the project on hold for close to 40 years. The Beach Boys continued to make albums for decades, often without Brian Wilson's help, but SMiLE and the full effect of Brian's vision weren't realized until 2004 when the album was released as a solo effort.