There is a confusing array of hammers on the store shelf, and then many more that aren't on the ordinary store shelves. You may be surprised to learn that there are cultural differences in hammers.
Here is a comparison of a North American with a British hammer. The head itself is similar but the British put a lot more meat behind with that chunky looking hammer.
The second photo compares ours with a Japanese hammer, which some people call a duck-bill hammer. They like that shock absorbing taper behind the head.
The Germans have square hammers.
Even in North America we have a lot of different hammers. All of the hammers shown here are made by Estwing Hammers.
Our standard general purpose hammer is a curved back claw hammer, and for ordinary use around the house you should get a 16 ounce hammer, not too heavy, not too light.
A framing hammer has straight claws, to allow a framer to whack in-between two pieces of wood to pry them apart. The claws on both of these hammers are only made for pulling out smooth common nails. All the better gripping nails like spiral and galvanised can break the claws and should be pulled out with a nail puller, not the hammer's claws.
Some of our framing hammers have a grid on the face called a milled face. This is not used for delicate work because it will mar the wood, but it does help to drive nails straight.
A CAT'S CLAW (small version) or BEAR'S CLAW (large version) is a cross between a wood chisel and the nail pulling ears of a hammer. You drive it under the head of a nail to get a grip on the nail and at least pull it up enough to get a hammer with more leverage under the nail for removial.
No matter which hammer you use, lining up the direction of motion of the hammer with the line of the nail -- and a flat strike of the head of the hammer onto the head of the nail -- not like in this photo -- is what helps to avoid bending nails.