I saw the Sandvich gun before you've posted the link to it and it made me laugh!
And then there's RubberFruit. This guy makes my second favorite GMod videos.http://www.youtube.com/watch?v=Nr-98GKVXK4&feature=channelhttp://www.youtube.com/watch?v=jZq8JyNl6Jw&feature=channelhttp://www.youtube.com/watch?v=NqDaMSk00wA&feature=channel
Does this count?http://www.youtube.com/watch?v=CTGrjcgSeAA&feature=related
THE SCOMBINEhttp://www.youtube.com/watch?v=-8Dkbcxh6Sw&feature=relatedHe may be more badass than Zero...