The most important consideration when evaluating a weapon is the ability to penetrate the human skull, destroying the brain. You must aim for disabling the brain through shooting, crushing and decapitating the zombie. The second most important attribute is the reliability of the weapon. If your weapon malfunctions/breaks while in close proximity to a zombie, you are out of luck. This is why military grade weapons is the most recommended. The third desired attribute is the volume of noise your weapon creates during combat. Firing a rifle from a window at a single zombie will instantly attract a horde from the surrounding areas, snowballing into a losing situation. This is also going to be covered in the Tactics page. The fourth desired attribute is the proficiency you can operate the weapon. If you have never fired, reloaded and disassembled an AR-15 then on-the-apocalypse training is not advised.
Some other factors to consider when choosing your weapons:Taking into consideration all of the attributes listed, it is impossible to recommend a single weapon set that will work for everyone. If you are not comfortable using a machete, an extremely effective weapon, you should not use it. However, this can work the opposite way. If you are a master morning star swinger, something developed in the last few hundred years might be worth looking into as well.