Another vote for the Maha if you can swing it. Ours in almost daily use now for 3+ years. Same model is still good even now. Fast, and slow charging as well as conditions batteries. It is big, and it is pricey, but if doing a lot of batteries, don't think there is another that can match it.
That being said, many of todays 2 and 4 cell chargers will do more than one chemistry for much less money.