I read the Zombie survival guide when I was about ten years old. I thought it was real right up until my grandma told me it wasn't
Seriously though, the best weapon against zombies, for me, would be an automatically loaded crossbow (the small ones you can strap onto your arm)
Lets face it, it's silent, as accurate as you need against a slow target who wont try and dodge, excellent piercing for destroying their brain effectively, re-usable ammo (!!!) and almost completely silent.
The low recoil is a bonus too for someone who hasn't got experience dealing with guns. The only problem would be the the reload rate, so I'd have to have a fast, crowd clearing gun as a sidearm (some sort of high caliber pistol to shoot legs off) and a good spear or something to keep them away from me if they got too close for comfort.
Of course military backing and a fully operational laser battle tank with jets, ICBM launching capabilites and an omg pwn gun on top would be the ideal but hey... have to make do with what you've got.