The Kuroshitsuji OVAs are honestly the best anime media of the series. The three best parts are Ciel in Wonderland, The Making of Kuroshitsuji II, and the Tale of William the Shinigami. They are all fun and lighthearted comedy. Do not go into it expecting serious content. They are all great because you can get a deeper look into each character, especially background information on the shinigami. Even if you were not huge on the regular series storylines, I think these are fun to try out if you enjoy the manga. I am not even into Black Butler anymore and still find these to befunny.