As a (wannabe) figure skater, I was already predisposed to liking “I, Tonya.” But I was blown away by how surprisingly powerful and poignant it was. It’s “GoodFellas” on ice: darkly comic and often just plain dark, but always breathtakingly alive. Margot Robbie is heartbreaking as the disgraced skater and Allison Janney just tears it up as her abusive mother. My rave, at RogerEbert.com.