Venom is hugely influential on a variety of styles of metal. Rising out of the NWOBHM, Venom was much faster, more raw, and apparently evil. The band's stage show was an influence on black metal with their over-the-top faux-Satanic lyrics. More than anything, that stage show just displayed the twisted sense of humor that would come to characterize Cronos and company. Venom also had a major influence on the formation of thrash metal, so of course I am completely on board.
FAVORITE ALBUM: WELCOME TO HELL