Best NiMH AA's you can get are probably GP (Gold Peak). It's what alot of folks use in RC Cars, and what I safeguard my cars with.
You can imagine what happens to a $500-$5000 RC Car/Plane when the radio dies because you tried to save $2-5 on a set of AA's.
I'll never make THAT mistake again - cost me nearly $200 in parts to repair a car!
They're probably only a couple bucks more for 4 AA's than that $20, but worth every penny. I just pulled out a set of 4 that I hadn't used in nearly 2 years, and they still can use nearly 70% of their rated capacity! Not bad for deteriorating on the shelf for almost 2 years!