The only ones worth mentioning are my explosive double barrel shotgun and instigating sniper rifle. Also have stuff like two shot 10mm but honestly it's not that great, very low dmg output in comparison.
I didn't care for the explosive shotgun.... I killed myself too often. (shoot an enemy at close range, and YOU are withing the AoE as well.)
The explosive combat shotgun is crazy OP - you just don't need another gun at all.
You just have to avoid back blast from using it too point blank, and also be wary of collateral damage to friendlies. Apart from that, it easily kills everything in the game (if you have the drum mag).
So far, only 3 that I found useful for my rifleman/pistol/sneak character:
-plasma infused 10mm pistol (equipped with silencer is a great, quiet infiltrating weapon)
-combat shotgun that does 25% more damage (don't remember the exact name, but it's a stopper if I get in a crowd and have to shoot my way out, short range)
-2 shot assault rifle (medium range, semi automatic mutant killer)
Still looking for that perfect recon sniper rifle.
My third PC (Survival STR/CHA all weapons but no crafting no PA build) found a Nocturnal Auto 10mm that improves damage deep into the night, that would be perfect for my night sniper build to clear houses with although I do enjoy the Deliverer. Problem is the PC that found it is a drunk who sleeps off the night in raiders dens after clearing them. Maybe he needs to find Cait for motivation to stay up all night. My BOS PA PC has a blast clearing the Glowing Sea with his Wounding Combat Shotgun while he svcks down the Mysterious Serum (cause he shot that annoying scientist with it...) I do not use Legendary crafting mods, I prefer more random PC development to keep each play thru unique. Although a good mod would be legendary transfers between chars since sometimes the weapons just do not fit the PC.
Many of those listed I have yet to find. IMO, the bestest combos are/would be:
10mm -- Staggering
.44 -- Staggering
.38 -- Endless (for auto fire)
.45 -- Explosive or perhaps plasma infused, have had both and both are good
Shotgun -- Incendiary (works very well, and without the friendly fire negatives), not sure what "Violent" or "Terrible" do but those might be good
Last toon had a "Quick Draw" double barrel, but the toon wasn't really built for VATS so it was a bit of a waste
I definitely would not use an explosive shotgun as I use it with a sawed off barrel and only or close or point-blank range.
.308 - Instigating (for sniping)
.50 - probably would also wish for Instigating
Minigun - explosive definitely, that just sounds like it would be worth totally retooling a character to be a heavy PA if I ever found it, which I never have
Lasers - not sure, I wasn't impressed with the better criticals effect of the "Righteous Authority" but again, the toon wasn't built for that . . .
Many of the Legendaries seem like they are really only optimally effective with highly specialized builds, but then again there is no "theorycrafting" in the game, so that is probably wrong
Explosive .308 combat rifle. When that ammo gets low, Irradiated Assault Rifle coupled with the Le Fusil Terribles, for those long distance relationships, Kneecapper .50 Sniper Rifle. I have the World Series Bat, but rarely use it, maybe against a rad roach.
That is indeed, the BEST use for 95% of them
Some of the combinations are absurdly useless: Exterminating Rolling Pin, Troubleshooters Combat Knife, Nimble Mini-gun, etc.
I kept my Bleeding Fatman, I do need one sometimes, and that was the most ridiculous one I found.
Exploding Mini Gun
Instigating Gauss rifle
I'm level 97 and these two destroy everything quickly