If I have to narrow down my favorites of the ones 
I've seen... they would have to be:

1) Outlaw Star
2) Vampire Hunter D: Bloodlust (not on list) oops
3) Castle in the Sky or Jin-Roh

It's weird, all of what I've seen I've liked.  
Though, I will have to admit when I first saw 
Grave of the Fireflies, I was bored out of my 
mind and kept looking @ the clock thinking, "this 
isn't over yet."  Then I watched it again when I 
needed to become tired, so I could to go bed... 
and I really liked it, and still do.  Strange, eh?