There are too many problems with using magnetic force.
First of all, as Captainproton said, the gravity acts on your whole body. Wearing a magnetic suit would not be it, because it's only the suit being subject to the force. Implanting magnets in the body, how much is enough? Are you suggesting we have everyone walk around with adamantium skeletons? Where on the body are we going to implant magnets or metallic bits?
Secondly, having giant walking magnets can create all sorts of problems, like disrupting nearby equipment and so on. Every person will be a mobile magnetic field. What happens when two such people come close to each other? Or in fact, think about what will happen if you had two or more magnets within the same person.
Thirdly, magnetic force does not work like gravity. It's more powerful, but it follows an inverse cube law, whereas gravity follows an inverse square law. I.e. if you double the distance from the source of gravity, the gravity gets 4x weaker, but doubling the distance from the magnet, the force gets 8x weaker. So you'll be getting a lot of force concentrating very close to the magnetic source (e.g. the floor), and getting drastically weaker the higher you go.
Not saying that going the magnetic route is impossible, but it creates way way more problems than trying to simulate gravity via spinning mechanics and so on.