Manga Arcs That Deserve a Proper Adaptation

I keep thinking about how some arcs get rushed or skipped entirely. A faithful adaptation is not just panel-for-panel; it is pacing, quiet moments, and letting characters breathe. Which completed arc would you want a dedicated season for, and which studio would actually respect its tone? For me, it is the later parts of a long-running series where the anime caught up and then went original. Curious what everyone