Energy blaster
These Energy blasters were used by the Preachers on Pete's World to kill the Cybermen. They could easily blow off a Cyberman's head.
The Tenth Doctor modified some blasters to penetrate the heat shields and Polycarbide of a Dalek. The blasters disabled the Cult of Skaro's weapons, though the Daleks quickly adapted and regained control of their weapons. (DW: Doomsday)
Upgraded versions of these guns were developed by the parallel world's Torchwood and used by Rose Tyler, Jackie Tyler and Mickey Smith. They fired a narrower, more opaque beam which could easily destroy a Dalek. (DW: The Stolen Earth / Journey's End)
The weapons room of Torchwood Three contained blasters, but the room was locked when Lisa Hallett attacked so they could not use them. (TW: Cyberwoman)
The Cybermen in the 51st century permanently incorporated these weapons into their arsenal. (DW: A Good Man Goes to War)