19. Emma Stone
Best: La La Land
Emma Stone has that special brand of charisma that makes her watchable in almost everything she's in, and there's a sort of easy accessibility to her performances that makes her incredibly sympathetic. That goes especially for La La Land, which relies not only on her chemistry with Gosling, but also on her ability to be more sympathetic than him (him following his dream HAS to appear to be an act of romantic sabotage), and she sells it perfectly.
She's an everywoman character, blighted by continued failure, but still boasting the kind of moxy the golden age leads would kill for, and it's impossible not to fall in love with her. Even if she chose the wrong man.
Worst: Movie 43 (2013)
Nobody who made Movie 43 deserves any sort of credit, and whether it's true they were all cast because of owing favours, there's no getting around that fact. Stone absolutely isn't the worst thing about the movie (that's probably Gerard Butler), but by God she must wish she hadn't been roped in at all.