Usually the degree certificate or diploma and the full academic transcript or mark sheets for each qualification, plus any grading scale printed on the documents. The university's admissions page or the evaluation service will say exactly what they need.
Transcripts are where the detail lives: course titles, hours or credits, grades, the grading scale and sometimes a final class or rank. We translate course names faithfully rather than renaming them to sound like US courses, and we keep the original grading notation so nothing is lost in conversion. Any legend on the back explaining the grading system is translated too, because evaluators rely on it.
For graduate admissions, US universities may also ask for proof of degree completion, a provisional certificate or a thesis approval. If a document has a ministry stamp or an apostille on it, we translate that as part of the document.