It's definitely a value judgment, but I'm not sure if that entirely precludes it from also being a factual statement, or at least a statement based on facts, as well. If there are certain objective parameters that are looked at in forming the rankings, then to that extent, it would also be a factual claim as well.

Opinion. No value judgments, no statements a la "this is better than that," etc. are objective/factual.

The value judgments can be based on a lot of objective data--stuff like whether students wind up in careers in the fields they majored in, stuff like their incomes in those careers, etc., but there are no objective facts in the vein of "It's better for students to wind up in careers in the fields they majored in rather than wind up working at McDonald's," "It's better to make more rather than less money," etc. Those things are inherently opinions.

If you're only ranking things in terms of objective data, then that's a fact. Like if you list schools in order of average LSAT scores or something, but that doesn't amount to the school with higher average LSAT scores being objectively better than the other schools. It's not objectively better to have higher rather than lower (or medium, or whatever) LSAT scores.