from my experience, i used a lot of diff rechargeable batt before and here is my review (simple one la)

1) energizer - the lifecycle is really short, no matter what they say. after a few hundred recharge, you will find it doesnt hold the charge very long

2) GP ReCyko+ - good but expensive and its not powerful enough to power some appliance! its f***ing strange!!

3) Sanyo eneloop - best rechargeable batt IMHO. bit more expensive but the charges lasts a lot longer and also it manages to power up devices where the GP couldnt!