Here's one I would nominate - a Nitecore Intellicharger i4. It will accept a variety of battery chemistries - nimh, Li-ion (what I am currently using) in AA.,AAA, C, and 18650 configurations. It stops charging automatically and I have had no problems, but I have been using only protected li-ions. There are other units that will do even more, but this model is working well for me. The cost was somewhere around $40, as I remember.

I am sure Chaos can add more to this.....