I made some tilapia and a few shrimp with a Thai sesame lime marinade. The marinade turned out amazing on the shrimp, but not as well as I had liked on the fish.
The key to adding more flavor to your marinade is by adding extra herbs and spices. Read the label on your marinade to see what herbs and spices are already used, and then add more of your own. This brings out the flavors and adds more depth.
For this one I added dried cilantro, garlic, and sesame seeds to spice it up. I just needed to marinate the fish a little longer. Or, you can always make your own marinade instead of the jar stuff which has more sodium. I buy bottles of marinade for convenience sometimes, but always check the sodium content, and preservatives.