BrickWarriors' LEGO Gun of the Week is clearly one of our favorites- we've featured it three times! But given that it is from Star Wars, it seems an obvious choice as a favorite LEGO Gun. Thanks to Flickr use NS Brick Designs for this great build. Here's a little info from Wookipedia...

"The DL-44 heavy blaster pistol was a type of heavy blaster pistol produced by BlasTech Industries that was used during the years of the Galactic Republic and the Age of the Empire. It was considered one of the most powerful blaster pistols in the galaxy, delivering massive damage at close range; however, it overheated quickly. There existed a carbine variation of this blaster including an extended barrel with the existing flash-suppressor and an attachable stock. This was used by Tobias Beckett in the trenches of Mimban before he deconstructed his DL-44 and gave it to a young Han Solo."