Basically.......if you're looking for a target rifle then go with the AR series.

If you're looking for a SHTF rifle then you definitely want an AK.

I own both types, some things I've found:

~The AR has better accuracy at 100 yards by about a inch.
~The AK has wayyyyy less moving parts, and can be field stripped and cleaned just about anywhere, anytime, in about 15 minutes.
~The AK used to be cheaper to get ammo for, now it's pretty much a wash either way.
~there's tons of parts and accessories for either to make them weigh just short of a metric ton.
~AR's occasionally jam unless you clean them every day....they usually clear out very quickly though.
~I can bury my AK in the mud, drive a tank over it, beat it with a hammer and drop it from an airplane........it'll still fire problem free without jamming.
~Tracer, starburst, and incendiary ammo is fun to shoot, and is readily available for either. ( Ammunition To Go : Your one stop for all of your ammunition needs! )

If I had to make a choice.......I'd go with the AK. Not to say I don't love my AR (Sabre Defense..GREAT weapon!) .......I just really like my AK's!