Crossed

Probably the best horror themed comic series in recent memory.

Imagine The Crazies combined with the Dawn of the Dead remake where instead of the undead coming to life or a biowarfare agent merely causing mass dementia, you have an unknown catalyst turning people into Earth versions of the Reavers from the Firefly/Serenity films where the infected areable to communicate with one another and weild weapons - including firearms - and are as hard to kill as fire ants.