Sometimes you want to trigger the next effect and have it stop the previously playing effect and you can do so by using a Wait 0, and a Stop effect. However if you want to do this for the entire cue list, a simple script could do that automatically for you.
// NewGO -- assign this script to any trigger that you use to start effects.
// This script will automatically stop any playing cue in the list, then
// it'll start playing the next cue.
stop list 'A'
go list 'A'
After you create the script, you'll want to assign it to the different places you can trigger an effect.
For example, if you use the Spacebar as your go, in Triggers, click on “Create New Global Keyboard Trigger” and make the shortcut the space bar, then the “Event” the script called NewGO.
If you still want to use the on screen GO Button, in the Triggers page, click on the SFX tab and add the NewGO script to the Event for the GO! Button.