What Wines Benefit From Aeration
Not every wine will improve, change or benefit from using an Aerator, but the majority of wines will. Very inexpensive and simple wines may not have further complexities that will unravel when exposed to air, in which case these wines will smell and taste the same. However any white or red wine that has more than one dimension will typically improve with even just a little bit of exposure to oxygen, in which case will greatly benefit from the use of an aerator.
Young and tannic wines with lots of concentrated fruit are a prime target for Aerators. These wines can soften and mellow within seconds allowing them to be fully enjoyed as close to their full potential as the age of the wine will allow. The same is true for quality older vintage wines that have experienced a good amount of bottle aging. These wines can sometimes be "tight" and really require a good amount of air to fully exhibit what it has evolved into, a perfect candidate for an Aerator. Even many white wines can benefit from aeration as they can be as complex, if not more, than many of the best red wines out there.
There is really very little harm that can be done in using an aerator, so it makes sense to use one on just about every wine that would like to open up and enjoy. You may want to be careful with those extremely older vintage wines, as sometimes they have a short shelf life once the bottle is open. So an over exposure of air can bring it past its enjoyment phase and right into decline. And remember, it won't take a simple wine and make it complex or improve overall quality so if your light Pinot Grigio still tastes like a light Pinot Grigio after using an Aerator... it is probably not the Aerator's fault.