"Superlative work" refers to work that is of the highest quality or excellence. It means that the work stands out and surpasses expectations, demonstrating exceptional skill and achievement. Full definition
Amanda Peet has been a welcome presence in film and TV for the last decade, but she's doing superlative work on HBO's «Togetherness» as the gorgeous, floundering sister to Melanie Lynskey's unhappily married mother. (backstage.com)
There's little doubt, however, that the movie, even during its less successful moments, benefits from the thoroughly (and uniformly) superlative work of its various actors - McDormand and Rockwell are especially magnetic here - and there does reach a point at which Three Billboards outside Ebbing, Missouri becomes far more engrossing and captivating than one might've anticipated. (reelfilm.com)
Hüller and Simonischek do superlative work, creating a relationship that feels genuine in its mix of affection and exasperation; neither Winfried nor Ines ever intends to hurt the other, yet the disappointment just keeps accruing on both sides, until each snaps in his / her own way. (film.avclub.com)