Is living on Mars the Best Option?

Recently in class we were discussing overpopulation and perhaps colonizing Mars by at least 2023. After all, Mars shows some similar salt deposits that can be found in Rio Tinto Basin, Huelva. These salt deposits are coherent with water. Life on Mars has long been debated over its existence and potential existence (you can read about life on Mars here). While people are adamant about colonizing Mars, does anyone know about some of the potential harmful effects that it can cause?

Recently in my physics class we were discussing magnetic fields and an interesting picture was shown. 

This picture shows the earth's magnetic field protecting earth from most of the suns radiation. Even when the poles flip, the earth will still mostly be protected from the suns radiation.  However, when you compare this image to an image of Mars you will see something interesting. What is shown is less protection against the suns radiation. The fact that there is increased radiation on Mars, and thus an increased risk in cancer is even supported by NASA.

NASA has even begun a debate of whether it is safe enough to colonize Mars. Some have suggested instead of colonizing Mars, we should consider the possibility of colonizing the moon first. You can read about the benefits of colonizing the moon first here.

So my question to others is: Is living on Mars the best option or is there a suitable alternative? Furthermore, is colonizing a foreign planet necessary?