It's unfortunate that your parents aren't a bit more understanding.  Everyone has an interest in *something*
The fact that you're interested in specific items imported from Japan should be a non-issue.  They're probably equating
anime with the domestic kiddy-crud, and then hear about the Pokemon craze, thus forming a very negative bias.

Are there any local anime clubs around your house?  If you aren't already, I would make an effort to get to their
meetings.  I may have avoided what you're going through by doing that.  Anime may be one of the only bright spots in
my otherwise boring life.  It is the one thing that is guaranteed to get me out of the house (besides work)--I'd
veg out in front of the computer otherwise.  I've met quite a few great people through some of the local clubs--I think
the defining moment when my parents saw it wasn't all that bad, is when I hosted a get-together when I was still
fairly new to anime.  If you can get to a convention, go--even if all you do is sit around talking to people....


One last thing....
Have they actually *watched* any of the shows?  You might want to try showing them things aimed at more mature groups,
maybe Evangelion, Lain, El Hazard, or Kenshin.  Sailor Moon, Rayearth, CCS, and the like would *not* be a good 
idea, and would probably reinforce their negative opinions.

Hope everything turns out ok...