I'm a college student, and need to be able to listen to music in my room without annoying my roommate. I also need to be able to drown out the noise around me, like the guy next door playing guitar and singing in a falsetto at all hours, or the guy across the hall watching South Park loudly at 4 am. Sound quality is also important, of course, but I'm far from an audiophile; I just want my music to sound good.
My parents got me Audio-Technica ATH-M50s for Christmas, at my request, because my research led me to believe they would suit my needs best within the price range (<$200). Any reviews I read of them said that noise isolation was pretty good, and there was minimal sound leakage. Well, I unwrapped them and immediately started listening to something on my phone at a reasonable volume (~50%)... and my mom, halfway across the room, started singing along. She could hear every word. I don't want to do that to my roommate. So these aren't going to work. Other than that, they're great, though. They don't really offer much in the way of noise isolation, but when I'm playing music, I can't hear much of what's going on around me anyways. Again, though, I really like these headphones, but they don't really meet my needs in terms of sound leak.
Does anyone have any recommendations of headphones of similar sound quality and similar price with better noise isolation/sound leakage?
(Sorry if any of this is stupid; again, I'm not an audiophile and I really don't know what I'm talking about, but advice is appreciated.)