How big is too big a tank? Is there a limit?

When it comes to looking for a tank for your fish, you can get numerous different sizes some of which may be perfect for someone but may not be for you if you are looking for something a little bigger either because you prefer to have a bigger tank or because of the amount of fish you wish to home in the tank.

When it comes to buying a bigger tank, how big would you say is too big and what would you say the limit is?