The NR USB is a decent choice. I went with a Dinotte 200L myself, and liked it so much I eventually bought a 140L taillight, though a PB superflash is "good enough" on the back. I just got the 140L because I want a searchlight on the back for fog and heavy rain.

The Dinotte goes on sale on their website for $100 (if you supply your own rechargable batteries and charger) occasionally. Try looking at their website at 6AM - for some goofy reason when I was shopping they'd put it on sale only until like 7AM.

I tried the flashlight route but found it very much lacking. I bought $25 flashlights and they both crapped out within a couple of months, the first one in 2 weeks. I determined that I'd have to spend $80 or so to get reliable, and since I can get a proper bike light for $100 I didn't feel that the kludgy method of using flashlights was sensible, for me.

You can get a heck of a lot of light from flashlights for $80, but I've never needed more than 200 lumens, in fact I am almost always running the 200L in 50% or even 25% power mode.

Also the runtime on the flashlights was pretty bad, I really wanted 3 hours.

I also didn't like that the flashlights cycle through all kinds of strobe modes and such. If I'm on low power and want to kick it to high (or vice versa), I don't want to have to cycle through 4 strobe modes to get there. The Dinotte sensibly separates steady and strobe modes, so when you're in steady mode, pushing the button just changes power. You have to hold the button for 6 seconds to switch to strobe modes, which totally makes sense to me.