Companion to the editorial best maps page. This is what's been downloaded most, not what's editorially most consequential.
What this list reflects
Download counts on the major mod-distribution sites. Discoverability matters - older mods accumulate downloads simply by being older. Marketing matters - mods featured by big creators get a boost.
Popularity is not the same as quality. Some of the most-downloaded mods are simple texture replacements. Some of the most ambitious projects have modest download counts.
What kinds of maps tend to lead the popularity charts
Map Editor base mods. Single-room interior replacements. Stunt arenas. RP-server-shipped MLOs (when distributed standalone). Texture overlays that change Vice City styling.
Heavy ambitious projects rarely top popularity charts because their installation friction is higher and their target audience is narrower.