: Source-controlled projects like the mcostalba chess_db contain over 30,000 annotation blocks, including commentary from masters like Tartakower and Reti.

: A major repository that hosts thousands of games sorted by player, event, and opening. Good resource for annotated games - Chess Stack Exchange

Finding "annotated" games—rather than just raw move lists—can be challenging as the commentary is often protected by copyright. However, several reputable sources provide high-quality free collections: