Circling the Donner Party wagon back around to 308 Battle Rifles...
I feel the FAL is the best option for the general population who don't want to spend $4000 on a single rifle rig. The 762Nato round is my personal favorite, but I have no plans on fighting a horde of zombies. In my little part of the world, distances are greater than in a city and cover exists everywhere.
If someone told me I had a relative who died and left me $5k in his will with the stipulation that he knew I didn't own a gun and I had to spend the money on guns I would buy:
Arsenal SLR-106FR AKM $1000
(15) 556 Circle 10 30rd Mags $600
(3000) M193 Ammo $1500
Glock 26 $500
(3 additional) Glock Mags $75
(2000) 9mm Ammo $600
Ruger 10/22 Stainless $225
(5 additional) Ruger 10rd Mags $100
(3000) 22lr Ammo $300
If he left me $7500....
Substitute this for the AKM:
Springfield Armory SAR48 FAL $2250
(15) FAL Mags $300
(3000) M80 762Nato Ammo $2100
If he left me $10k....
Substitute this for the FAL:
FN Scar 17 $2500
Trijicon TA11 ACOG $1000
LaRue Mount $125
(15) Scar Mags $600
(3000) M80 762Nato Ammo $2100