Of the Paraliminals, we've heard favorable reports about New History Generator and Self-Esteem Supercharger from people with depression.
The most dramatic reports have come from people practicing the Active Exercise of Spring Forest Qigong.
Regarding listening to more than one tape at a time: You will be better served by focusing on one goal (not one tape) at a time, unless the goals you would like to work on are minor, then sail away, sail away. When working on a goal, listen to as many different Paraliminal sessions as may support your goal. When listening to more than one in a day, be sure to give yourself at least a 20-minute break between listenings.