Well I am not sure if its the best, but I use a Maha four channel charger. I was using a two channel charger but something about that bothered me. With the two channel charger, you have to charge in pairs and they batteries should be in the same condition. Since there are many things that I use rechargables in, I am afraid I will eventually put two batteries of different charge level in the same channel. Example: A half drained battery and a fully drained battery. I do not know if it will overcharge the half drained battery, undercharge the drained battery, or a little of both. I prefer not to worry about it so I use 4 channel chargers and be done with it. I wonder how others feel about this aspect of battery charger.
I use maha 2200 because of the reviews I have seen on some camera sites. I do not know if they are the best but each review says that Maha does not over rate ther products.