IMHO the Cygolite Hotshot is the absolute best bang for the buck light you can get. Pretty sure it's the brightest rear light available for $30 or less, that also is USB rechargeable. I did have a L&M Vis180 Micro... for a day. Didn't even use it on one ride. The first time I tried to plug it in, the USB port inside the light broke off the PC board. Returned it and got the Hotshot. Yes the 180 definitely has a wider beam pattern which is nice, but the price and build quality (the rubber strap "mount" is pure crap) really turned me off from it.

I also use a Cygolite ExpiliOn 700 front light, which IMHO is also probably the best rechargeable self-contained light out there, i.e. no separate battery pack with wires running all over the place. The bar mount included with the ExpiliOn is VERY good, also. It also comes with a helmet mount that I rigged up to attach to the stem of my other bike.