There's a whole galaxy of guns out there (and more than a handful of swords, too). I want to know what everyone's favorite set-up for a weapon is across the systems?
I'm partial to any sort of shotgun with the Solid Slugs (from Rogue Trader: Hostile Acquisitions) and some sort of pistol grip set-up on it. The whole Arbites shtick is fun to me, so I love blowing away heretics so solidly. The modified bolt shells for shotguns (same book) also make me happy. I've also seen some kind of ridiculous gun capable of obliterating most opponents at 400 thrones, and saw a gun that abused Ork upgrades to dead 12d10+144 damage or some such nonsense (I think it shot flaming lightning that dealt Explosive damage?)