Which language(s) are the easiest and most difficult for English speakers to learn? Why?

Question

Assuming French or Spanish are the easiest languages for an English speaker to learn, then which are the most difficult?

How much more difficult are they?

For example, if learning 'x' amount of language in French takes 'h' amount of guided learning or study hours, then learning Cantonese or Vietnamese will take 'y' times 'h' amount of time/effort. In this example, what number will 'y' be?

Try to provide evidence if you can.

Answer 1

French- easiest as they follow the same script and similar rules of Grammer
Japanese- Most difficult, no similarity with English at all.

Answer 2

Spanish? Easy. Navajo? Impossible. With a little application one can learn conversational Spanish.

Navajo is full of glottal stops and inflections. There is an saying, "If you don't grow up speaking Navajo, you will never learn to speak it." It is an Athabaskan language.

Answer 3

I've heard an american person speak japanese before and I think it was pretty good. I live in Hungary, Europe and to tell you the truth a lot of americans try to speak hungarian but it's really hard for them to pronounce a lot of the sounds and there are letters like á, é, ö, ő, ü, ű, ú, ó, í and so on. You should look it up...hungarian.