Fresh eggs are the best and if I could, I would have some chickens outside of my NYC apartment. To test the freshness of your store bought eggs, put them in a glass of cold water. The fresher the egg, the faster it will fall to the bottom. This is because the air cell, or space between the egg white and the shell increases as the egg ages causing a greater ability for the egg to float.
You can also judge the freshness of an egg by observing the viscosity of the egg white when cracked. The more the egg white spreads in a pan, the less fresh it is. On the other hand, the less the egg white spreads from the yolk, the fresher it is. I hope you learned something new and have an eggcellent day!