I have also heard great things about the Sanyo Eneloop batteries; as far as I know they lead the market in terms of quality and longevity.
However, if you read the reviews of rechargeable batteries on Amazon.com, you find that Amazon’s rechargeable “Amazon Basics” batteries, are really just re-branded Eneloops! And the good part is that they are only about half the price! I haven’t actually used them, but my cousin has, and as far as I know he is very happy with them.
Speaking of Amazon reviews, if you look at the batteries you currently own on Amazon, you’ll see quite a few people complain that after a while a couple of them won’t hold a charge at all… At least one person said that they are actually about 2000-2200 mAh instead of their claimed 2950. I was rather incredulous myself, I’ve never heard of batteries with that high of a capacity. The highest quality Eneloops are only 2550 mAh!
If you’re interested, here’s a link to the higher powered Amazon Basics, and here’s a link to the higher powered Eneloops. These are the 2500 mAh ones, there are also lower powered versions that are only 1900-2000 mAh. Keep an eye out for mAh ratings when you buy, I’m quite sure both the AB and Eneloop high-powered ones are black colored, and the low-powered are white.
I actually use Tenergy AA batteries in my speedlights. I got them because they were a pretty decent battery for a much better price than the Eneloops. (That was before I knew about the Amazon Basics batteries.) Tenergy makes “regular” and “Pre-Charged” (a.k.a LSD) batteries. The best price I’ve found on them as far as I can remember is at All-battery.com The Low Self Discharge ones are only 2000 mAh though, so you may want to go for the higher powered “regular” ones, or else get the Amazon Basics/Eneloop LSD ones which have 2500 mAh. In my experience the Tenergy ones don’t seem particularly “powerful” but they do the trick for me! Like I said, I haven’t tried the AB/Eneloops, so I can’t really compare them. If you know you’re going to be using them, and “top them off” beforehand, then you’ll get better recycle times. (Not to mention they’ll last longer).
Hope you can make sense of all my ramblings!