In order to make our decision, let's first clarify the circumstances of our zombie apocalypse and then use those as a basis for establishing selection criteria.

First, the zombie apocalypse will last indefinitely, and there will be no hope of rescue, as all government and military institutions have ceased to exist in any meaningful capacity. Secondly, weapons will be selected only from what could realistically be scavenged in either a common urban or rural environment.

Assuming this dire situation, I have based my weapon decision on three primary factors: [b]durability[/b], [b]frequency[/b] (e.g. how common it is), and [b]usability[/b]. The last one is particularly important: remember that you're going to have to carry this crap around 24/7, so for me that automatically eliminates novelty answers like samurai swords and polearms. Not to mention the likelihood of finding or possessing true versions of these weapons. Those $20 replica katanas have tangs that will snap in half the first real blow, so unless you've spent upwards of $1000 on a "true" weapon forged to resemble those actually used in battlefield conditions and not just sold to anime enthusiasts at conventions, these are probably out.

Being a frequent Renaissance fair enthusiast, I can say this much about axes: that crap is awkward as heck to carry around all day. Whether a fireman's axe or a wood-splitting axe, carrying one on your hip all day is incredibly uncomfortable, and can lead to likely self-injury over a sustained period of time. Polearms being carried all day? Forget it.

Edged weapons are almost entirely out. Swords of any variety actually require a good amount of upkeep: even the miniscule body like present in a normal person's touch can cause discoloration or rust in even the best steel, to say nothing of constant gore from zombie fighting or exposure to the elements like rain.

The crowbar, as inspired by Gordon Freeman, is a popular answer and a step in the right direction. It requires little upkeep and no formal training to shatter zombie skulls. I see only one real issue with it: crowbars are freaking heavy. They are made as prying tools for jobs like opening broken doors or removing manhole covers, not bashing in skulls. Anyone who survives the zombie outbreak past day three can be assumed to be physically fit, but even Conan the Barbarian would get tired after the 10th zombie skull.

My melee weapon of choice? An aluminum baseball bat. Finding one should be child's play, as they exist in every Wal-mart (and probably every suburban household). Perfectly cylindrical, it would be child's play to tie a rope around and carry on the back all day. Its form factor was literally designed for hitting objects at high speeds, which is why it's the knee-smashing weapon of choice for the non distinguishing gangster. While not having the sheer impact of a crowbar, the reinforced aluminum's high strength store right ratio means you can club dozens of zombie skulls and still have the lung capacity remaining to sprint away from the remainder of the approaching horde. For those doubting its lethality, I would encourage a quick YouTube search. An aluminum bat is most definetely capable of shattering a skull wide open.

Just for fun, let's do a firearm also.

With a finite supply of ammo, availability of ammunition is almost exclusively the defining factor here. Any handgun that uses 9mm ammo would be my first choice, as 9mm is almost 5x more common than any other small caliber round.

Eventually I would try acquiring a Ruger 10/22. As far as rifles go, the 10/22 is semu-automatic and has been in full production for 50+ years, meaning there are 10's of thousands floating around in the civilian market. And with good reason too: durable and accurate, it's not sexy since it's the rifle old grandpa hunted with, but it's proven, and should you need replacement parts they could be readily scavenged, not to mention the availability of useful attachments like scopes. Its 22LR ammo is also the most popular on the civilian market, so ammo would be abundant (relative to other firearms).

Tl;Dr Don't be bought with sex appeal. Get a baseball bat and a 10/22 rifle.