It all depends on what your into really. I typically watch action/super power type things like Naruto, Bleach, One Piece, Dragonball Z, Full Metal Alchemist, etc. However Death Note is a brilliant detective thriller series. I hear good things about Lupin the Third but haven't really checked it out. Studio Ghibli films are also excellent, my personal favourite being Princess Mononoke closely followed by Howl's Moving Castle. But explore because there are thousands of different types of series out there.