There are many options for pets, but some like to start out small. Others like to have small ones simply because their landlords will not allow them to have a cat or a dog. Hamsters are very popular when it comes to small pets, though they certainly won't live as long as a cat or a dog, they can have a decent lifespan. When you get one, you do have to find the best hamster cages that you can afford to keep them happy and healthy for as long as possible.
The hamster cages that most of us had when growing up were rather simple. They had a metal cage, and the tops and bottoms were either closed or open. These hamster cages had a running wheel, and then food and water apparatus. That was usually about it. They worked well enough, and some had a ball they could put their hamster in to let it run around the house without getting hurt or lost. It was also great exercise, but not being a hamster myself, I couldn't really tell you if they really enjoy it or not.
The hamster cages of today are a bit more fun, probably for the hamster and the owner alike. You can still find the old kind, but the newer ones don't have any bars at all. They are made of a plastic that has holes in it for proper air ventilation, and are often in really neat and bright colors. The plastic is see-through, so the hamster is not hidden most of the time. Not only that, the hamster cages can be as big as you want, as they have additions that can go on and on. If you have more than one, this is a fun thing to do.
Most of these hamster cages can be put together with tunnels, or the tunnels can go in and out of the same cage. That makes them a lot of fun, and gives the animal more room to roam and more exercise to boot. What you want to spend on your hamster cages will be up to you of course, and you can buy each piece on its own, and then add more later if you really want to. Just remember to keep them clean, and that when you have more, you have more to keep up with. However, most hamster owners don't mind the work, and they think their little critters are well worth it.