an AR can shoot sub-moa out to 400 yards, can hold many optics, scopes, lasers, and your soda, has the best ergonomics of probably any rifle out there right now, can cause you to have collections come after you, is a good reason to buy a gun case that costs more than a gun, comes in pretty much every caliber (and can shoot most of them on the same lower), can be disassembled with a q-tip and three fingers, is a good reason to get into reloading, makes cleaning something to do when you have nothing to do for the whole day, and aggravates fanboys and chair commandos who don't have the money for one and bash it to no end about how fragile, unreliable, and weak it is.
an AK can shoot straight most of the time, can hit a capitalist scum out to 280 meters, can attach a decent red dot to it, can be had for the price of an Xbox360, won't jam unless you do something stupid (like clean it), takes a hammer and some blood and tears to disassemble it all the way, has the ergonomics of a weedwacker, doubles as a club/boat oar/tent spike/shovel, doesn't need to be babied because the varnishy paint flakes off every time you use the safety, is available in four main calibers (but you need a new gun for each one, which makes the AK a good reason to buy more guns to add to your collection - and all four of them combined cost less than one AR), can be made in your garage with a hammer, drill, hole-punch, and a swig of vodka every two minutes, and aggravates fanboys and elitist yacht owners who bash it to no end for being cheap, inaccurate, and not pretty or elegant.
...I choose both.