I have also tested AA alkalines and have found less than a 10% difference in capacity. Thus I tend to buy on price. I personally have had good luck with Kirkland brand AA's from Costco (about 25 cents per cell). Spud
I use rechargeables, but I only have 6 of 'em, so today I bought a huge pack of Costco AAs for $10 to just outfit everything for a while. I am not sure how well they will do, but they were super cheap so I am gonna try 'em out...