The Ripper! Sure, the Shishkebob is cool too, and does more damage, but you just can't beat the satisfying sounds and visuals of the ripper. Besides, it owns when taking down super mutants with miniguns. I seldom take more than 0-2 hits, as long as I make them come to me.
Corner ambush FTW!
Other than that, the Chinese Assault Rifle is very nice, and the Sniper Rifle paired with Sneak is Godly. Damn Greenies can't shoot me if I remove their head with one-two shots from afar. I could go on like this for a long time, mentioning frags, mines (bottlecap yay!), Hunting Rifle, Combat Shotgun...
This is probably why I'm a walking heap of guns. I carry so many different weapons that I shouldn't even be visible underneath them