First thing that comes to mind are the fleija weapons from Code Geass R2. There are in the last couple of episode.
Vash the Stampeade from Trigun destroys an entire city in episode 16.
The first episode of Nichijou also has one.
Zanz Bonus Points Tally
8bit_samurai: 1, CodeZTM: 1, Eake4: 2, ibabrak: 5, Mirkosp: 4, tipsd9video: 1, uncreative: 1