[BirAdam]

I dunno. I love the German language and didn’t struggle too much with it. To be honest, the variety of accents is far harder.

Every language is pretty much equally difficult if you want to gain near native fluency (even Esperanto). If you are aiming for quick business level fluency, English and Mandarin are easy due to the abundance of resources. Generally, however, sticking with your native language’s family is going to be easiest. I personally think that most of the English speaker trouble with German is that it is at once both familiar and frustratingly foreign due to the Romanization of English after the Norman conquest, while Spanish or Urdu is just foreign. The speaker carries no assumptions with himself/herself into the learning process.