on what AK was there favorite ? Brand, country etc.
Mine is the Russian Saiga AK's for a few reasons
They can be picked up pretty cheap from a gun show ( I got mine for $350&360)
I have two a 223 and a 7.63x39
after a conversion kit built guided and parts needed to make 922r* or what ever the number is it was around $500 I love both of them and never had a problem with them.