My dear meeting professional. One of the main reasons your panels are boring is that YOU have not set your panel up for success. Sure, you identified a slot of time, selected a topic and wrestled up a moderator and some panelists. You consider your job to be done. At this point, your job is HALF done. You still have some fundamental groundwork to cover with your panel moderator who will bring your vision to reality. Meet with your panel moderator (either face-to-face or virtually) and have a chit-chat about what the panel could be.