Eh, Theorycraft™ says that an outer layer or two of standard, with a couple(2-3) layers of basic inside/below it, an empty space, and then 1-2 layers advanced around/encapsulating systems deeper inside the ship would offer the best balance of protection-to-mass-to-area.
The discussion of exactly how-to armor something the "best way" is as old as weaponry. I personally put it towards "who's piloting it" to determine which is the best.
If it's mainly AI or an aggressive player in control, then the best bet is to go with heavy armor on the "front" as that's the direction most likely to be under fire. Both are probably going to "face tank" and "roll the dice" well past shield collapse.
If it's piloted by a "scaredycat" player, medium-light armor towards the back and sides is better as they'd turn tail and run at low shields until the shields recharge. The lighter armor would allow more "speed tanking" play style as well.
Other players (too lazy to search though the old armor threads) point out "all or nothing" armoring styles where they'd only armor the important to combat stuff, like the main chunk of reactor and primary weapon systems, and put all the mass of an otherwise much larger ship in those concentrated areas and leave the rest open to being evaporated. That style comes mainly from USA and UK Naval Doctrine, armor the ammunition and leave the rest open to even small arms fire.
I say it comes down to how you play. If you're not afraid to get battle scars, armor is for you. If you think every block is precious, you're probably not going to stay in combat with anything that can drop your shields anyways making armoring irrelevant.