Im no expert but Im sure the general rule of thumb with 18650 batteries is to steer clear of anything with “fire” in its name eg Ultrafire. Also avoid 4sevens. Ultrafire mah ratings are utter bollocks and with a bit of googling you’ll find plenty of bad experiences with them.
If any of you are going down the 18650 route I suggest you buy only quality cells like AW,Redilast, EagleTac, Enerpower.
For the average Joe who doesn’t want the hassle of a hobby charger for the above batteries look towards a Pila charger or at the very least an Intellicore i4 or Xtar
Avoid the 2 pin generic chargers like the plague.
Each to their own like but I feel more confident using a cell which I know is a genuine Panasonic cell with a Protected PCB that has a quality control system in place.