I prefer a beefy revolver. Has the added benefit of being holstered, and gets the job done. Admittedly, I dunno how they fare against hulks, as I try to avoid fighting those. But they take out NPCs and brutes well enough. If you wanna be absolutely sure that whatever you’re pointing at turns into little giblets on the road, not much beats a shotgun at point-blank range.
Though to be completely honest, there’s so many guns in this game and not much difference between them. Kinda feels like having multiple 9mm pistols or .22 rifles is kinda pointless, since guns tend to be more towards endgame anyway, simply because ammo is so hard to find in abundance. And you don’t need skill to shoot at basically point-blank range.
So really, just whatever there’s ammo for, preferring larger calibre rounds over smaller ones.