If a bunch of 'friends' are comming then you shouldn't worry. They are your friends and they already like you. And it's a party! No one's gonna' "What's this anime? That guy's alooser. Let's get out of here." There will be a great atmosphere. "What's this DVD? Paprika?? Awesome!!"

I suggest you don't leave everything lying around. Put your Gungams on a shelf and your DVD's in their rack. If people see them like that they'll figure it's a hobby and not an... obsession.