My native language is Bengali and therefore, you can assume that I am not bias toward any European languages. I mostly looked at Spanish, German and French Wikiepdias.
German: Even though German language have lot of information; however, vast majority of the information are not cited. German has second most articles after English but the depth of articles are not good. German wikipedia has the least cited materials from all the languages that I looked into; even the featured articles are not cited extensively like the English or French. German Wikipedia is not organized (ie putting articles on categories, setting up different projects to target related articles). German tend to borrow English and other language's vocabulary words compare to other major European languages (probably except for Italians). German usually borrow English words when describing technological or scientific terms that the world normally use (ie I view this as a positive).
Spanish: I was kind of disappointed in Spanish Wikipedia. More than half of materials on Spanish Wikipedia directly copied/translated/pasted from English Wikipedia and other language Wikipedias. Even most of the featured Spanish articles are copied and posted from English articles. For example, Spanish Wikipedia did not upload a single image; they use images uploaded to the other language Wikipedias like English, German and French Wikiepdia. Spanish language articles tend to be good at Spanish related stuff but not good on other stuff. It is not very organized.
French: I was highly impressed with French Wikipedia. I would rank French Wikipedia to be the second best after English. French Wikipedia is highly organized (ie categorized, setup different projects to target related articles and etc). French Wikipedia articles have high degree of depth. Unlike many other Wikipedia's, French Wikipedia do not copy/paste from English Wikipedia as much (even though there are lot of articles that copied and pasted from English articles) as other language Wikipedias do. I was highly impressed with featured articles because they are highly cited and are really good articles, many of them are even better than the English featured articles.
Portuguese: More than 3/4 Materials are copied/translated/pasted from English Wikipedia and other language Wikiepdias.
German: Even though German language have lot of information; however, vast majority of the information are not cited. German has second most articles after English but the depth of articles are not good. German wikipedia has the least cited materials from all the languages that I looked into; even the featured articles are not cited extensively like the English or French. German Wikipedia is not organized (ie putting articles on categories, setting up different projects to target related articles). German tend to borrow English and other language's vocabulary words compare to other major European languages (probably except for Italians). German usually borrow English words when describing technological or scientific terms that the world normally use (ie I view this as a positive).
Spanish: I was kind of disappointed in Spanish Wikipedia. More than half of materials on Spanish Wikipedia directly copied/translated/pasted from English Wikipedia and other language Wikipedias. Even most of the featured Spanish articles are copied and posted from English articles. For example, Spanish Wikipedia did not upload a single image; they use images uploaded to the other language Wikipedias like English, German and French Wikiepdia. Spanish language articles tend to be good at Spanish related stuff but not good on other stuff. It is not very organized.
French: I was highly impressed with French Wikipedia. I would rank French Wikipedia to be the second best after English. French Wikipedia is highly organized (ie categorized, setup different projects to target related articles and etc). French Wikipedia articles have high degree of depth. Unlike many other Wikipedia's, French Wikipedia do not copy/paste from English Wikipedia as much (even though there are lot of articles that copied and pasted from English articles) as other language Wikipedias do. I was highly impressed with featured articles because they are highly cited and are really good articles, many of them are even better than the English featured articles.
Portuguese: More than 3/4 Materials are copied/translated/pasted from English Wikipedia and other language Wikiepdias.