my reraising range includes AK and AKs if the inital raise is <5x. (sometimes there are exceptions to this, if I think the inital raiser is weak postflop, or I think there is a good chance he is raisng a hand that I dominate)

my rr range for over 5x inital raises include AA, KK, and 45s-TJs and QQ situationally.

However, on a different note, my favorite line with AA is to sometimes call a 5x opener, or call a reraise if someone raises over my 5x opener. (I only do this if its guarenteed to go HU to the flop). Then I have various strategies to get the villan to stack off to me with TPTK or a lower overpair, which usually involves making a disproportionately large bet or raise on the flop. Sometimes I even just open push. I'm finding this works pretty well, where someone who might have mucked AK, AQ, or KK-JJ to a reraise gets aggressive postflop or cannot lay it down.