take your pick, got makita and bosch.
both brilliant makes, although i prefer the bosch.
they vary from 9.6, 14.4 and 18volts.
the problem i found was that one of the bosch ones only gets occassional use and so the batteries turn to shit after a while and need fully charging, then flatten in seconds, then repeat a couple of times and all is back to normal.
doesn't happen with the makita, but it isn't as old and gets used a little more.