i'd go for a gun, a shotgun or an automatic rifle with selective fire to semi (for hunting). you'll run out of bullets, but at least survival will be easier when you have one. it'd be a good idea to get out of a city and into the country when you still have bullets too.

i wouldn't stake too much on a bow. zombies will attack in a mass and you would need awesome accuracy and speed to kill them all. and even though you can make more arrows, it's probably pretty hard to do that in the wild with barely anything. plus they're rather bulky.

I am already living in the woods so assuming the zombies would be in more populated areas I am not really worried about them hearing whatever shots. So in that case I would say the AA-12 if I had enough ammo. Otherwise just a few (3 or so) 12 gage shotguns that way when one person is reloading the other 2 can fire. However you cant go wrong with an Ar15, A 1911, and an old fashioned boat oar  .

As much as I love archery I might use my bow for hunting but I wouldn't bet my life an using them against a dozen or more zombies, espicially when only head shots count.

Expanded magazine semi-auto shotgun with solid shot exploding ammo.

That way one shot does the deal no matter where you hit

Obviously after a while, what with civilisation collapsing - you'd have to shift to  a purely muscle power weapon.

Don't think a bow without techno tips is going to do much towards stopping a zombie.
So I'll go for a sling with bolas ammo and an axe

Tangle their legs and then either leggit or saunter over and lop off their heads.  

YOu know i keep mentioning bolas ammo - I'm going to have to make some aren't I ? lol

Give me a good old Colt 45 in each hand and lots of pre-filled ammo clips.  I don't want to get into the "will a 45 knock someone down" discussion again, though it was a good one.  Suffice to say that a 45 does have lots of hitting power and the capacity to blow off zombie limbs.  If I run out of bullets then I'd use a sling.  There are always plenty of good stones around here.  I'd also keep my old 1905 army sword bayonet handy just in case.

I'm more of a primitive weapons guy, so I'd go with longbow and slings. The longbow would give me good range, and if it's a zombie horde, how accurate do I need to be? The sling would be for much shorter ranges, and also for when I run out of arrows.

Let's not forget the importance of not only good weapons, but good strategies. If we had a pinchpoint, we could have pikemen holding the zombies back, while slingers rain down a deluge of rocks. Plus, any boulders or large pieces of debris at hand could be pushed down, causing more damage. If you can get yourself in an area with one entrance/exit and enough food and water to last you a while, you could hold off the zombies for a while. You could pick them off fairly easily, and you could even booby-trap the entranceway so that any zombies that make it through don't rally make it through.

Best ranged weapon?  15KT nuke.  All you have to do is put a pile of politicians in a large open area and let the zombies swarm them.  There is one question, "Is it ethical?"  It would be like hunting over a bait pile, it may be legal but will you be able to brag about it?  And also, where will your proof be, you vaporized all the zombies.  After a hand to hand fight, you have a pile of rotting corpses.  I will let each person decide.  Bill

I would go with a Winchester 94, 30-30 with a sling for backup.  You could hunt with the sling to conserve bullets, and use the sling to fight with if necessary.  The Winchester 94 is one of the most common rifles in America (if you are in the US during an outbreak), so you could easily find ammunition and spare parts.  A shotgun would work also.

As far as what would be best, if I could only choose one weapon I'd go with a sling (that is if I weren't allowed to craft one to go with a gun.  If I were allowed to make one, I'd choose a gun), mainly because the ammo is widely available.  If you are talking about surviving indefinitely, then you need a weapon that will last a long time.  Eventually most of the zombies would die off, leaving only a few stragglers.  A sling or melee weapon (such as a katana) would be ideal for these situations, especially at a time when society no longer exists.  A gun is nothing more than an expensive club if you don't have ammo.  (Also, with a sling you could put the cord through the eye of a sawblade to get an improvised melee weapon)