The Nitecore MH20 is a well regarded product, but the company cares about MAPs (minimum advertised prices) so deals are hard to find.
My favorite USB light is the Eagle Eye X6R ( Review ), but it’s not a turnkey product like the Nitecore. It’s been regularly offered for $24 from AliExpress (in China), but it presently is not listed (non-listing here ). This has happened 2 or 3 times before, so it will likely return to that location. And it doesn’t come with the battery or USB miniplug cord. Both are standard items, but 18650 batteries aren’t available at Walgreens – Amazon, or Batteries Plus or B+H. And if you use a protected cell, it doesn’t like anything longer than 69mm.
Another option is the new Manker U11. Here’s a Chinese company, FastTech, offering a good deal on it.
Again, there’s no battery included. My favorite battery source is Mountain Electronics. This is a good battery for the above lights. PayPal.