Don't forget about Ninja Scroll
http://us.imdb.com/Title?0107692 It's a classic. Well worth the time.
Vampire Hunter D: Bloodlust is better than the original. Both are worth seeing. VHD Bloodlust and Princess Mononoke are both great intros to people who haven't watched much anime, or assume cartoons are for kids. Ghost in the Shell is incredible, you can get into the heavy thinking in it or just watch the action, your call.
The Trigun series that's coming to Cartoon Network late night next week rocks. It's goofy, it's philosophical, it's got plenty of action and not everyone gets out alive. I love it. Heck, I've even got a Wolfwood hanging from my rearview window. Of course I don't know how much CN will edit it, but it shouldn't be too much.
Demon City Shinjuku
http://us.imdb.com/Title?0094995 is also pretty cool, but in a really campy way. Also not for the kids, even if there isn't any nudity. The english translation one liners go from, "Would she preferred I fucked her silly all night?" to "I'm going to kill you for the worlds sake!" I love that. It even starts off with a good guy getting shredded. Fun stuff.
Oh yeah, as far as cartoons go The Iron Giant is pretty damn cool. I don't have any more to say about that.
By the by, I picked up Castle of Cogliostro 'bout five years ago in a bargain bin for three bucks. Now I see it for sale for $20. Heh.