At this point in the rankings, Diane Keaton versus Kevin Costner is best read as a compact career snapshot rather than an all-time verdict. The biggest-hit category sharpens the box office contrast, especially because Diane Keaton's leading film creates the stronger single-release benchmark.

Commercial scale is another meaningful divider, with the career domestic box office measure giving Kevin Costner the larger theatrical footprint. The comparison therefore points leans toward Diane Keaton, with the most meaningful separation coming from the highlighted career measures.