My husband and I really love LP's. We love the oldness of them as well as the quirkiness of music available. Some of my favorites from our collection include Captain Kangaroo narrating Peter and the Wolf, a recording of Karajan rehearsing the Berlin Philharmonic on Beethoven's 9th Symphony, a recital by violinist Igor Oistrakh (son of David Oistrakh) of 20th century pieces, and various recordings of easy listening "jazz" from the 1950's and 60's.
Occasionally we will come across an instrument that we're not familiar with. Last weekend we picked up a record that features an ensemble of cello, viola, and glass harmonica. Surprisingly, it works quite well. Neither of us knew quite what a glass harmonica was, though, so we looked it up on Youtube.