Obitus Wrote: Add this: -noworkshop to your startup configurations in Steam.
This is kind of an extreme if you want absolutely nothing other than the base game. You can also manually select addons to disable while still being subscribed to them. On the main menu click "Addons." In there you have the options to "Enable all," "Disable All," or "Uninstall All." To manually select them to enable/disable click the checkbox and select one of the options on the left (Enable, Disable, or Uninstall Selected) to either enable, disable, or uninstall the selected addons. Or you can just unsubscribefrom the ones you don't want.