Today’s Pinyin-friendly font is Skarpa, by Aga Silva of Poland. It’s a bit quirky (e.g., second-tone o’s and lowercase q’s) but still sharp.

Skarpa was later modified into Skarpa 2, which is not free but which comes in several weights and types.

Most of Silva’s other fonts also can handle Pinyin with tone marks. Those are all commercial rather than free.