I have been using the XTAR MX4 charger for almost a month now, and so far, I am pretty happy with it. It supports multiple battery types, including Li-ion, LiFePO4, and Ni-MH, so I can charge different batteries without keeping three separate chargers around. The automatic battery recognition and charging cut-off are also nice features, as I do not have to worry about leaving batteries in it longer than necessary.
You can get it here: https://link.amazon/A0dua97Er
The four slots are convenient, and the LED indicators make it easy to check the charging status at a glance. It is compact, simple to use, and does what I expect from a battery charger without making things complicated. My only minor complaint is that it does not have a display showing charging current or battery capacity, but that is understandable at this price.
Overall, the XTAR MX4 is a solid option for anyone who regularly uses rechargeable batteries. It costs less than $16, supports several battery chemistries, and has useful safety features. Now I just need to stop buying rechargeable batteries long enough to enjoy saving money on them!