We are talking trash metal here. Fast, loud and aggressive would be a correct way to describe their music, though Megadeth has also created some excellent ballads. The main and (now only) permanent member of Megadeth is Dave Mustaine who also has been a member of Metallica. Their albums are rich in fast and very heavy guitar work which was a result of Mustaine being fired from Metallica. You can listen here to a collection of their work, enjoy...