Personally, if you've seen the woven plastic they use to make luggage these days, you could actually fashion yourself a nice set of improvised armor out of it. Teeth, nails and bone won't puncture it, and cutting it is very hard without a blade. Getting snags is down right difficult and it's very flexible so it's easy to move around in. With the right weave, you could make it breath in certain spots (under arms, crotch, inner legs, neck) without sacrificing any protection.
Best of all, it's quiet and easy to get a hold of. Any Mall, Department Store, or major retailer will have a department, section or store with potential access, as well as access to the tools to fashion your suit.
Of course, if creating your own armor seems far fetched or over the top, then look for Riot gear on police / prison / military individuals who have fallen. Or go straight to the source from (hopefully) un-looted stations.
Full plate mail is a bad idea. Basically it's heavy, cumbersome, awkward and noisy. And to those who say "so what?", I would like to mention that while one or two zombies may not pose an issue and you would be able to potentially dispatch them (assuming you could swing a weapon, as the finer points of rifle / handgun use is above the dexterity found in a suit of armor), what happens when more then that are alerted to your noisy self? Out run them? Even the slow ones will catch up when you rest, that armor's heavy. Climbing of any sort is out, and the farther you go, the more that will give chase. Eventually, without help, you'll be swarmed and smothered to death in your own suit of armor.
Chainmail is a better option, but yeah, noisy and not very functional. And really, how easy is that to come across from all points? That may work for those people who have a Middle Ages Festival nearby constantly, but from a practical stand point, you'd be better off planning for what you have around you, or is widely available to most people.
