I'm more afraid of Spanish than any other language.
Feels like it'd be harder than Japanese, but I've studied Japanese for a while now, so I'm biased.
Not sure why, I feel like the "closeness" of Spanish to English is deceptive as to its difficulty. The only advantage you have going in is really getting a free pass on select vocabulary. The rest just comes down to brute force and exposure.
I like the "distance" of Japanese because for some reason it's easier to file away words and concepts that aren't "english like" at all.
the nice thing about spanish is that the written words are all phonetic ---