If you find yourself in an undead invasion,I would recommend three types of weapon:
1)A melee weapon,they don't run out of ammo.
2)A shotgun.They have a wide spread spread pattern,and are widely regarded as the best weapon to kill zombies with.There is no chance of missing the brain with a headshot,whereas with other guns,a bullet may just graze the side of the skull.
3)An assault rifle(An M16,AK-74 or an AR-15 "Armalite")with NATO 5.56 rounds.
BlackHaku
I got a better weapon, A hot dog!