I'm using the Sanyo charger with "Refresh" function. The model number behind my set is NC-MQR03RNU. Costs around $45-$50, usually comes with two 2,500mA NiMH batteries.
Four slots total - 4 x AA with two of the slots accomodating AAA batteries as well.
The charger is small and very light.
Whilst NiMH batteries are very tolerant of partial charging, I still use the "Refresh" function (full cycle - discharge then charge) my NiMH batteries every few weeks just for the heck of it. The function is probably a lot more useful if you have Ni-Cds.
Lensman from CS is in charge of developing them, and he pm'ed me to tell me about his company's chargers. They cost much less than the equivalent Maha chargers, have individual circuits (ie each battery gets one monitoring circuit, rather than in pairs). The 30 minute charger works as advertised, comes with a little (very silent) cooling fan built into the charger, and has a car adaptor thrown in - great for charging while you're driving (since it charges so quickly, this is practicable). Only drawback is that you should only use the Ultra Rapid batteries produced by Fiamo, as they shorten the life of normal NiMH batteries. But these are quite cheap anyway, so I stocked up on the Ultra Rapid batteries as well (2000 mAh)
The 120 min charger takes a little longer, but can handle my legacy batteries. The Fiamo batteries are quite reasonably priced as well (2500 mAh).
Best part is that I did not even have to drive to town - Lensman kindly agreed to drop them off at my place. I'm not saying he'll do that for you.
How do they perform? Very well. I'm still using the Ultra Rapid charged about a week ago in my torchlight, and it is as bright as ever.
You can pm Lensman if you're interested. Don't ask me about the pricing - all I can say is that it's much cheaper than the Maha or the Lacrosse.
Since we're on the topic of AA chargers, mind if I ask if anyone has experience with the charger that comes with the eneloop batteries? I need something small and travel-friendly, so that and the eneloop seems good for me...
Oh yar, let me know where I can get them for a reasonable price too