This font, without a doubt is my all time favourite. Well, at the moment anyway! It was designed by A. M. Cassandre in France in 1930. It's the ultimate Deco font I think. I actually used it in one of my prints: Dove of Peace. I am working on a project with some super talented Australian Etsy illustrators and I might actually incorporate this font into my part of the project.
Another one of my favourite fonts that I haven't as yet used is this charming English one below by Lewis F. Day. It was designed in 1900 and I think it a very elegant example of Art Nouveau lettering. I looks a little like Japanese calligraphy I think.
Pardon the shadow at the edge there - I scanned this page from my Fancy Alphabet book which you can find here.