The way I read your question, the only case you have against your roomies is that they lost your DVD. They may not like what you like, but they have no right to lose it from you accident , or no, you deserve to get recompense for that either replacing the DVD, or giving you the money to do so yourself. I'm married to a woman who won't watch anime for £100 cash, which is fine because I won't watch her soaps, or reality shows for love, nor money either so it's a balanced stalemate. Everyone at work know about my hobby, they take it, or leave it, and personally I couldn't give a toss either way anyway. But your roomy needs to replace that lost DVD pronto.