That's what Caprese should be. It's all about the quality of the ingredients.

Granted not everyone can go and pick one's own tomatoes but there are lots of farmers markets or organic stores out there that will do the job.
Fresh, plump and juicy are what you should be looking for.
If in doubt don't be afraid to smell the tomatoes to see if they actually sell like tomatoes, they should!

As for Mozzarella, go for fresh from the deli rather than in the packet in the cooler.
Of course buffalo mozzarella is traditional but other types (cow's) are just as good.
Just make sure that it's not too rubbery, it should be soft and a little stringy, and ask to taste if you can. 

Basil, use fresh with good quality extra virgin oil if you can.
It will keep in the fridge for a week or so but be sure to keep it in the fridge as the leaves are not cooked and left out for a long time can become a food hazard.

For the balsamic reduction, don't buy expensive balsamic as it's a waste.
You're going to cook it so save the good stuff for another time.
Here's a link to the Balsamic Vinegar Reduction recipe I added to the Sommelier Chef site.

This recipe should, hopefully, allow you to make a dish that shows tomato and mozzarella in a new light.
A quick tip for eating it: use a serrated knife or a steak knife to cut this, a plain dinner knife will make the stack slide around the plate!

It's simple but delicious.