Spirited Away
Really good flick, look at what kind of damage its doing on the IMDB charts. #1 animated movie, #48 on the all time top 250 list. Voice acting for the USA version really well done.
Once you see that one, if it floats your boat, check out
Princess Mononoke
#3 on the top 100 animated list and #118 out of 250 on the all time list.
On the non animated side, lesser known but top movies I would recommend are:
Amelie
Romantic comedy.
The Professional (AKA Leon)
Not really obscure but a GREAT movie. Action/Romance
Once Upon a Time in America
Crime Drama. Not on par with the Godfather but still very very good.