And even though it's NOT a gun, it will be seen on movie screens in the summer of 2011, and it IS the Most Powerful Weapon in the Universe, so... this makes my list...
Until you're up against someone in the primary color Yellow, at which point you're useless.
As it is though, the Trek V/VI phaser isn't bad, although it shows off it's "real gun" heritage
The TMP/WOK is probably third in my list, but I still like it a lot. Don't care for the blinky lites but oh well. :rolleyes
Original "Battlestar Galactica" was actually released as a theatrical film (in Canada I think) so you can grandfather that one in if you really want to. :lol