I may be a purist but I prefer icons that are made of official art only. Good sources for that is the Axis Hetalia webcomic site and the artist's blog (tho' be careful 'cause he sometimes posts art from another one of his comics, some of the characters look rather similiar). The web site for the anime doesn't have a lot on it but it does have some pictures of the chibi characters, which is nice 'cause those are no longer up on the webcomic's site.

Webcomic: http://www.geocities.jp/himaruya/hetaria/index.htm
Artist's Blog: http://himaruya.blog61.fc2.com/
Anime: http://hetalia.com/top.htm