I haven't done any modding yet, and still have much to explore.
Right now, my go to is a glow sighted hair trigger combat shotgun.

Depends on the situation:

For Raiders and small critters: 10mm with 15 points of Fire damage. Got this one early, and with the mods, is my sweeper.

For everything else: combat shotgun. Right before I ended the game for the night, I found the Terrible Shotgun. Can't wait to try it out. With my Lone Wanderer 25% damage, this thing is going to make exploring the rest of Boston much easier.

Though, there's usually not much resistance by the time I get where I'm going. My buffed sniper rifle clears out any stragglers before they know I'm coming. Spending the mods on my combat armor to reduce sway was the best investment one can make.

I also found an endless ammo gauss rifle. Haven't used it yet, but I've a feeling I won't be needing it.

The Terrible Shotgun. Oh how nice it is to have my old favorite back in my hands again. *smooches it*

Modded semi automatic combat shotgun with stagger. After I killed a behemoth with it at level 15 I realized how useful it was. Excellent against everything but shines against bullet sponges like Yao Guais and Death Claws, kite and shoot.

Overseer's Guardian with strongest semi-auto .45 receiver, suppressor, and reflex. Can pick off someone long range, or take out a group of close enemies easily.

I like my never-ending 10mm pistol or whatever they call it, the feature where you don't have to reload. Can just light up close enemies without having to worry about how many rounds I'm dumping into them.

I like my Gauss rifle with plasma damage a lot too.

Screw it, I like all my weapons. That's why I carry them

.308 semi-auto combat rifle with reflex sight and bayonet. Nothin' fancy but it gets the job done 90% of the time.

For inside I've had good luck in VATS with the regular old fully modded 10mm pistol. I use a scoped sniper rifle for outside long shots and then switch back to good ol 10mm when the bad guys get close. With the gunslinger and Marksman perk these weapons do a surprising amount of damage and the 10mm and 308 rounds are fairly common.

Legendary combat rifle (adds 100 radiation damage), modded to .308, medium night vision scope.

First Character: My Kar98k. Fully customized Hunting Rifle, does over 200 damage, not a legendary. Or my fully modded out Righteous Authority Danse gave me. (Rifleman focus.)

Second Character: Not really sure, I think a 10mm Auto-Pistol of some kind. (Commando focus.)

Third Character: Institute Pistol with a holo-sight. It does wonders so far, and I have lots of ammo for it. (Pistol Focus.)

My "Sprinting Wolf" Legendary Gauss Rifle that lets me move 75% faster while aiming for heavy enemies and my "Angel" Legendary 10mm Pistol that does an extra 10 plasma damage for quick fire fights. Both modded for highest damage efficiency

Spray and pray

I destroy almost everything within seconds. My favorite weapon so far, as long as I have enough ammo.

These are 3 weapons I have all the time... here are my main perks... RIFLEMAN (4/5) + MR SANDMAN (3/3) + NINJA (3/3) = 5.3x DMG for ranged sneak attacks.

Ranged = Relentless 50 cal sniper: long light barrel, markman's stock, large quick eject mag, long recon scope, suppresor. 120 DMG X 5.3 DMG bonus.

Close combat = 44 cal 7 bullet revolver: advanced receiver, bull barrel, comfort grip, short scope. 176 DMG no bonus but fun weapon to blow heads off or shoot a leg off. No bonus but BETTER CRITICALS (3/3) + CRITICAL BANKER (3/3) makes this the most OP of the bunch.

Medium range = 5.56 rifle with 50 RADIATION DMG: advanced receiver, vented barrel, short stock, standard magazine, long recon scope, suppressor. 98 base DMG x 5.3 DMG + 50 RAD DMG per bullet.

Level 50 PS4 Survival difficulty

The Railway Rifle if I have ammo for it. I never get tired of pinning people's head's to walls.

If no ammo for that I use a modded combat shotgun and combat rifle.

Kellog's Pistol for my gunslinger run. It's really all I need as long as I got the ammo.

I have quite an extensive list of weapons in my armoury. I tend to avoid the weird "magic effect" legendaries unless they make sense. So far none of the ones I've found have so everything is built up from stock. I'm at LVL 18 at the moment with a Hunting Rifle (Medium Scope, Long Ported Barrel, Marksman Stock, Compensator, Standard Magazine, Standard Reciever) backed up with the original 10mm Pistol I got from the Vault (Advanced Receiver, Glow Sights, Quick Eject Magazine, Long Barrel, No Muzzle Attachment). Both are doing me perfectly fine for the time being, until I run out of ammo of course. Then I'll switch over to another set until I run out of ammo for those. Of course none of my weapons are really where I want them yet as my level is too low for the higher crafting options.

In the garage I've also got one of most other regular guns in the game. My first long term rifle was an upgraded .45 Pipe Revolver Rifle (Short Scope, Long Light Barrel, Compensator, Hardened Receiver, Marksman Stock). I'm looking forward to seeing some of the more advanced weaponry, most notably Plasma weapons and the Gauss Rifle.

I try to keep some realism in my armament. I frequently asked myself how I could carry the 5 rifles and shotguns plus handgun and supersledge I sometimes had with me in the past. So now it's one long gun, one short gun and a melee weapon.

My main weapon after several trials is a 40 rounds semi-automatic combat rifle modded for highest damage with a short-distance scope, cal. .45 as I still don't have the level for the .308 conversion. (The short gun is also one ruled by the rifleman perk, a short double-barreled shotgun you could carry in a holster. Melee is Kremvh's Tooth.)

Modded up 10mm and Modded up single shot combat rifle with short scope.

With all my ultra light armour, and a couple of pieces of VATS enhanced stuff, I can empty a clip of 10mm for over 700 points of damage in one VATS session...it takes down deathclaws.

is it just me or are ballistic pistols really underwhelming? the .44 is decent but nothing seems to compare to the rifles in terms of damage when fully maxed out.

overseers guardian

My no legendary .44 does around 300 damage, probably a low compared to double shot gauss.

But the thing about pistols is you can fire them 2-3x as often in VATS and GunFu for endless crits.

Pistols are already relatively too strong. Nobody would really take a handgun as main weapon in a dangerous world with frequent gunfights. It's a pity that there are no features to bring the handguns advantages to shine in the game if you don't use VATS. A shield option for the weak hand (with a reduction of pistol damage) would be one.

Yeah pistols, melee, and unarmed are lackluster outside of VATS in this game.

Depends on what I'm doing. Took out a couple towers filled with raiders, snuck around and used Sidekick a lot. A 10mm handgun with circle dot scope, silencer, extended mag (going to remove, not needed), and powerful receiver/barrel setup. It kicks kind of hard, but I liked it a lot.

So far my goto weapons are:
Dead Eye - .308 sniper rifle
Goldeneye - .50 cal sniper rifle
The Pounder - semiautomatic long barrel shotgun
Life & Death - long barrel and glow sighted combat rifle
Sidekick (mentioned above)
Righteous Justice (just in case I need an energy weapon).

Plus whatever mines I find laying around.

Pretty early in the game I got a Instigating 10mm pistol. I used it for ages, upgrading it when I could. It pushed me towards stealth because the combination of a sneak attack plus the double damage for uninjured enemies was very powerful (at least it was playing on hard).

Late game my mighty gauss rifle is what comes out when anything looks challenging..

BTW for challenging foes I use an instigating Fatman (that my companion has to carry, hehe).

Kneecapper calibrated powerful sniper rifle.

Calibrated powerful receiver

Long ported barrel

marksman's stock

quick eject mag

long night vision scope

suppressor

Current main weapon the laser who do double damage on unharmed enemies bought in diamond city, moded to sniper specks but with an reflect sight as I use is as an assault rifle.

Main weakness is the low ammo capacity, have an 0.50 sniper rifle for sniping, benefit is that it has an silencer making it more practical to snipe with, Spray and Pray for masses of enemies or bosses.