There may be a few artists where I only own/enjoy one album but I probably haven't heard many (or in some cases, any) others. Horace Tapscott's debut (which I just got recently) is a good example. It's an interesting avant garde jazz album but by all accounts, he went totally free jazz from that point on, which isn't my thing, so I probably won't check out any others. There are probably other examples of artists who radically changed their style after their first album, like Traffic. But even though I vastly prefer "Mr. Fantasy" (one of my favorite Brit psych pop albums) to the 2 albums that came after it, I still enjoy those. So I can't really think of many artists where I literally only enjoy one album but there are a few where I vastly prefer one to the others. Add me to the chorus who vastly prefers "Lamb Lies Down" to all other Genesis albums.