children dvds

after reading a posting about the baby einstein videos, we put them on my son's xmas list. he is 5 months old and we have 4 from the series (bach, mozart, doolittle and einstein) and have been enjoying them immensely! does anyone have any other suggestions as far as educational children's videos/dvds? is there a website or organization that rates videos for kids?

any thoughts on this would be greatly appreciated!
lissa