No pair always makes me beat AA. I wish they did!
Statistically 66, 77 or 88 are the best to have when facing AA as they make the most straights that AA cannot. 88 is marginally the best of those.
They are easier to play from the point of view of losing fewer chips to AA than higher pocket pairs for the times we do lose too.
We will be in fewer 3 bet or 4 bet pots with them to begin with so we're playing smaller pots than if we had a larger pair.
We will also be in fewer situations where we have an overpair to the board, saving us from spewing off all our chips compared to if we had something like QQ, JJ or 10 10 when facing AA.