The Unity3d globalArgLine. Allows you to define a per default global configuration for all your unity3d builds.
Combined with a plugin like EnvInject, allows you to configure most of your projects in one place.
For example: use:
-logFile "$WORKSPACE/unity3d_editor.log" -quit -batchmode -executeMethod $UNITY_EXECUTEMETHOD $UNITY_EXTRA_ARGUMENTS
and define per project the UNITY_EXECUTEMETHOD and optional UNITY_EXTRA_ARGUMENTS variables.
Is overriden by the per project argLine
value.