Green flu outbreak! The population is almost entirely divided into:
infected and thus homicidal and stupid;
those killed because they were infected;
those killed because they were thought to be infected;
those who killed themselves because they thought they were infected;
those two killed themselves because they thought the situation was hopeless;
those who died in RTAs trying to flee;
those two died in the rioting;
the crews of nuclear-powered submarines and carrier battle groups that were out at sea and remain unexposed;
tiny, remote communities that have so little contact with the rest of the world that they haven't been exposed either;
you guys. You're immune. Presumably, you're not the only ones, but you're the only ones in this neighbourhood.
Supplies are running low, and it's time to leave.
You've got two decisions to make. One's where you head. The other's which of the following indestructible magical items you take with you. For some reason, the magic just won't work for more than one item in any one person's possession, so it's just one each.
The 9mm pistol with a magazine that refills itself with live rounds every time you drop it from the gun.
The .338 LM rifle with a single round that refills itself every time you put the empty case back in your pocket.
The 20-gauge shotgun with an ammo saddle that refills itself every time you feed a round from it into the magazine.
The waterproof box of strike-anywhere matches that refills itself every time you close it.
The flask of fresh, hot, green tea that refills itself every time you screw the lid on.
The bottle of hand sanitiser that refills itself after every squeeze.
The Pez dispenser that refills itself after every click.
In L4D and L4D2, you all went with the pistol, in one calibre or another, but long term, on a trek from Pennsylvania to Yellowstone to live on geothermal power, with winter coming? That flask could save your lives every night for a month.
Oh, Willie McBride, it was all done in vain.