My subsectioned and listed-in-importance from most to least list:
Critically important:
Food
meat, for energy
Calcium-rich drink or foodstuff. For bone health and to dampen gangrene's effect
Vitamins for those pinches where you need a boost
small stove, like a bunson burner or mini camping stove. If you are using a car, you can just use a camp stove
Weapons
Crowbar for bashing zombies with
high-caliber weapon (like shotgun) and ammo, to blow zombie's heads up
Tools
Pocketknife. Your all-in-one survival tool
a few spare radio parts for fixing anything you come across. You'll need those radios sometimes
radio for searching for survivors
Other
small medical kit. Just stuff like rubbing alcohol, wart remover, maybe something to stop bleeding, but if you aren't in
a heavily-infested area, you shouldn't be in that much risk for zombies finding your blood
a bike or other non-gasoline-powered vehicle if you have no way to get gas. Otherwise, just take a car
water purifier. Not an original idea, but a good one nonetheless
Important
Weapons
small pistol or similar. Good for swarming zombies.
a knife. Doesn't matter if it's a switchblade, butterfly knife, something on your pocketknife, or a butcherknife. It's a good idea to have.
rifle. Semi-auto, bolt-action or other. Should be pretty powerful. An M1 Garand is a good rifle.
Tools
gas mask or similar if there was a bioweapon responsible for your area's zombie infestation
LOTS of scrap metal. Good for welding to cars and making Hinda-Civic-Tanks
anything to keep you occupied while not sleeping, defending, or attacking. Like a computer or GameBoy.
Other
lighter fluid. You never know when lighter fluid will come in handy
lighter for setting fires and cauterizing wounds. Carefully.
lots of ammunition for a small weapon
Not very important
Weapons
high-caliber sniper rifle. Two shots can obliterate normal zombies
Tools
portable generator. Only if it can run extremely efficiently on fuel, or if it works some other way. Keep your GameBoy charged!
Other
clothing. Not too important, but if you don't want to lose your nether regions to a zombie, go ahead and wear pants
...I have no life :\
