The other part of the re-chargeable battery picture is the charger.
The chargers you get at radio shack, walmart, best buy, home depot, etc are all crap. Spend a couple extra $ on a MAHA or LaCross and your batteries will reward you. I was able to rejuvenate some 1999 vintage NiMH that I use in kid toys now after I thought they were worn out due to poor quality chargers. So I'm running near 10 years on those batteries and the only reason they are not used in my gear is I've replaced them with the low self discharge.
I've standardized on Sanyo Eneloop and have been running them for over a year now and I get run time equal or better than Alkaline even after they have been sitting for months.