Oblivion shipped with thousands of bugs, and the Unofficial Patches are the community's decades-long answer. UOP fixes the base game, USIP fixes Shivering Isles, and UODP cleans up the DLC. The Official 1.2.416 Patch is the last official update Bethesda ever shipped. Install all four and the game is genuinely stable for the first time.
Ranked by hand, not auto-generated. Every mod links to its full page with install guide + compatibility.