As a life-long fish keeper, the answer to this question is not a simple yes or no. First, there are the differences between fresh-water set-ups versus salt-water. Having a salt-water tank is much more time consuming and high maintenance then fresh water set-ups.
For those looking for less maintenance, fresh water is by far the choice to make. The advantages to a fresh water set-up is that once the initial set-up is completed, the daily maintenance of the fish are basically just feeding and checking to see if there are any problems with the fish.
By looking for problems, I am referring to checking for unusual behavior, looking for any damaged fins, and checking for any signs of disease or fungus. By observing your fish for a few minutes everyday, you'll start to see what their "normal" behavior is, so that you can spot abnormal behavior. Plus, isn't the point of having a fish tank is to have something to enjoy everyday anyway?
Freshwater Fish also need weekly and monthly maintenance chores. Once the tank is established (i.e., been running for more then a couple of months), you still need to stay on top of checking the water quality of the aquarium. By water quality, you should check the PH level weekly (the amount of PH varies based on what type of fish you have) and the ammonia level (ammonia, even in small amounts, can be fatal to fish). Water softness/harness can also be a factor is you are keeping fish that are sensitive to the amount of harness (dissolved minerals) that are in the water.
As for monthly chores, the tank filter media should be cleaned or replaced at least once a month. Partial water changes are also of importance. An aquarium is an enclosed environment. Fish are excreting waste in the same water they are living and breathing. There is also decaying food in the tank producing ammonia. It is for this reason the tank water must be changed approximately every two weeks. When changing the water, a water conditioner must be added in order to remove any chlorine and other items in tap water that are harmful to fish. These conditioners can be found in most pet stores where fish are sold.
The good news is that once the tank is established, this type of maintenance routine is much lower in comparison to having other pets. If you enjoy a crisp, clean aquarium, then it is worth it to take these steps. If not, it could cause more problems down for your tank, making it higher maintenance.
When all is going well, then fish become an "easy" pet. But when problems occur in the tank, and your fish start to die, there is nothing easy about that!