Which Big-Data Frameworks have most simple interfaces?
I think that it is impossible to answer this question comprehensively, at least for the following reasons:


big data frameworks have different goals and target different knowledge domains, so the comparison simply doesn't make much sense;
most big data frameworks (and other programming frameworks, for that matter) have multiple interfaces, and frequently those sets of interfaces are significantly different (the intersection is small), so there is a risk of comparing apples and oranges;
trying to compare anything (in this case, interfaces), using simplicity as a criterion, involves a significant amount of subjectivity - what one person perceive as very simple, another person might find quite complex;
the variety and the number of big data frameworks is mind-boggling (for example, see https://github.com/onurakpolat/awesome-bigdata); the same applies to a related topic of machine learning frameworks (for example, see https://github.com/josephmisiti/awesome-machine-learning);
corollary from the points above: a comprehensive comparison (considering all the above-mentioned issues) would go far beyond the scope of a single answer on this site, in volume and effort - it would be more like a long research paper, a book chapter or even a book.