Right now, I'm very please with the new Uway VH200B (cost around $200). No problems with either of the ones I bought, clear night-time pictures (although a tad grainy, but still in sharp focus), and you can plug a black-flash flash extender into them and have the main unit run the flash extender (which I used on both when I had the cameras over food plots).
The only thing I don't like is the maximum of three picture burst mode. I liked the option of up to 9 burst mode pictures per trigger on the NT50B better.
That said, the Covert black-flash, Bushnell black-flash and especially the Moultire M-80 black-flash are all getting good reviews.