1. "Pet Sounds" - The Beach Boys
Themes: Being ahead of your time/Not belonging/Musical genius
This is undoubtedly the most famous album on this list, but I couldn't help it; it belongs here. Not exactly a concept album, it's also too good to simply be labeled a traditional one. Although The Beach Boys were huge hit makers in the '60s, lead songwriter Brian Wilson wasn't interested in just banging out the poppy, sun-soaked singles, so he locked himself away with his cowriter Tony Asher (as Barenaked Ladies once sang, "Lying in bed/just like Brian Wilson did") and spent years working on his passion project, i.e., his "Pet Sounds." A perfectionist, it took him several years, much to the frustration of his fellow band mates and especially his record company, which forced him to put out a commercial album in between his recording sessions. It was a long wait, but it was worth it. The result was an album that not only had the hits ("God Only Knows," "Sloop John B," and, my personal favorite, "Wouldn't It Be Nice") but also artistic integrityin other words, soulusing not only strange instruments like xylophones, jingle bells, and bicycle horns but also strange ways to play regular instruments, such as opening up a baby grand piano to manually pluck the strings in the opening of "You Still Believe in Me."
As for the concept, it can best be described in the song title, "I Just Wasn't Made for These Times." Wilson created an endurable masterpiece that has inspired millions, including forcing The Beatles themselves to answer back with "Sgt. Pepper's Lonely Heart Club Band." And my list ends how it began - just like a concept album!