I'd say they're equally difficult for an English speaker.
German belongs to the same language family as English, but their grammar, syntax and vocabulary are substantially different. On the other hand, French and Spanish are classified into a different language family, but Old English borrowed thousands of Latin and French words due to historical reasons. However, modern English core vocabulary, grammar and syntax are still somewhat closer to those of other Germanic languages. Germanic and Latin-based languagues are all Indo-European, which means they're more similar to one another than any of them is to languages like Arabic, Chinese, Basque, Yoruba or Japanese.