Do you need to be able to use a USB supply? Some people like this. I don’t, but it depends on what you need.
That having been said, many seem to like the Vapcell S4 plus. I have one and use it regularly. (When I just want to charge smaller cells at low currents. Otherwise I use my SkyRC MC3000).
Here is a thread on the latest V3 model:
Here is a comprehensive review, It is on the older model, but except for a couple of feature additions on the V3, it still should be accurate:
It covers most of the bases for many users. It can charge as low as 250 mA for LiIon cells and up to 3 amps. It can do capacity testing. It shows Internal Resistance, I believe the V3 also has a storage function (mine is a V2). It will charge LiIon and Nimh cells. A pretty comprehensive feature set.