For the longest time, we have been buying the smallest chicken eggs we can find whenever we need eggs. It used to be the case that we went for the largest kind, but nowadays, we stick to the smallest. Why? Because it is tastier that way.
See, we did some egg experiments. We bought various different egg types, we pretty much tried all the eggs available in the farmer's market nearby where we live. And after making different eggs using different methods and different egg sizes, we have come to the conclusion that the smaller eggs are the tastier.
You might want to ask why.
Well, it all has something to do with the proportion of the egg yolk to the egg white. Yolks typically do not vary in size. And that is the tasty part. Egg whites on the other hand vary in volume. So if you get an XXL egg and compare it with the S egg, the yolks might be of the same volume, but the XXL definitely has more egg white. So imagine making scrambled eggs using these two egg sizes. The XXL egg will give you more volume, but the taste density is definitely lower than the S egg. So if you compare the taste, the scrambled eggs from the smaller eggs definitely have a stronger taste than the XXL eggs.
That said, there are XXXL eggs available, and these for the most part have double yolks. Not every egg has it, but there's a high chance that there are twin yolks inside. But then again, I think these are more for novelty, than for the taste.
So there, if you want very tasty eggs, then try buying smaller eggs. If on the other hand you need protein and are after the egg whites, then I suppose the larger eggs would be for you.