I prefer a balance between AAs and levels, due to my playing style. I spend a lot of time experiencing as much of a level range as possible - I don't go for pushing through to the endgame quickly. To this end I have gotten a lot of AAs to round out my characters at each step. For example, at 63 my cleric has an odd assortment of 6 General (including run3, of course) as well as his Healing Gift/Adept up to 3 in Archetype, a level or two in Radiant Cure, Spellcasting Mastery. The basics. 36 AA or so in all. Now, though, I'm pushing for 64 or 65 for certain spells. My necro has 160AA at level 66, but that's just because necros can rake in exp like no other.
I've got no real need to go to 67 or higher just yet; I still need to get the spells.
Regardless of play style, many people state as I do that you should get the first 6 AA - usually run3 and regen3 - by 60. Where you go from there is up to you, but general consensus has been that up until Serpents Spine, you get far more AA and faster at 70, so people just push to that point and get all the req. 70 gear.