Mutagen Zombie
These zombies aren't technically dead, but they're not human either, having been infected by some manner of mutagen they've mutated into inhuman monsters designed for the sole purpose of spreading the infection, these are you Resident Evil type zombies, only a bullet to the head or extreme disruption of biomass will do, even then burning the corpses is highly recommended.
Or you could intentionally get yourself infected, sure it's a one-in-a-billion chance but your genetics could synchronize with the mutagen and turn you into Homo-Sapian-Superior, or a hideous freak.
Nanotech Zombie
Bad news, very bad news, much like the mutagen zombies but with nanotech, so they regenerate twice as fast, feed off ambient energy, and are probably smarter than you, i.e. there's no hope, you may not even get a chance to scream.
Cyborg Zombie
Not as bad as the nanotech zombies, but still pretty damn bad, the cyborg zombie is what you get when a cyborg becomes a zombie (no, duh) and if the whole undead thing didn't make them hard enough to kill before, now they're practically invincible.
Not to be confused with the cyborg living dead, they're people who have cheated death by altering their failing bodies with technology, they tend not to be infections, unless we're talking about personalities.
Armageddon Zombie
So hell's full and the worst of the worst are fighting their way to the top and breaking out, now corpses all over the world (and the occasional weak minded person) are being possessed by these malevolent spirits, ushering in hell on earth until the end of time.
Sodomites will have fun.
Voodoo/Hypnosis Zombie
Not really a zombie as such, just someone who has been mindfucked into serving some twisted master, not really dangerous or even infectious, but you still need to be careful, they're surprisingly clever sometimes and can blend into general society.
Necromancy Zombie
Skeletons, liches, wraiths, vampires, zombies, etc.
Get a big stick and start pummelling, these D&D has-beens are pathetic.