What was your Избранное Rosario+Vampire episode?

Hehehe ^w^ mines was Math and a Vampire, when Tsukune is falling behind the others in math and it is summer school for him if he fails the midterms. Yukari and Moka try to help Tsukune with his math in their own way only to find that their efforts have drawn the attention of Ririko, who insists upon extra lessons with her and her alone. Unfortunately, Tsukune's newfound proficiency in math from these lessons comes at the cost of his personality, and a bit of investigating reveals there is еще to Ririko than meets the eye, as she is a lamia, and a battle with Inner Moka later, Tsukune is back to normal. It turns out that all of that artificial knowledge was not necessary for Tsukune to pass the midterm. Mizore barely gets by while Kurumu fails miseriably.