Pick one pistol, pick one rifle/carbine, and pick one shotgun, that you currently own, and tell us why they are a “must keep”…
Bonus points for pictures. 
Pistol: Kimber Warrior, customized slightly by Novak’s. It’s been my primary training pistol and nightstand gun for the last 3 years. Stone reliable, just like my Glocks. Now it’s getting golfball’ed and I can’t say that I’ll sell a pistol that I’ve customized to my liking over this length of time.
Carbine: Armalite/RRA/TROS 9mm suppressed SBR. It’s quite the compact package. Cheap to shoot. Quiet. Reliable as hell. I’d certainly not part with my 5.56 carbines either, but the 9mm build is far more entertaining while we all wait for the world to end or whatever…
Shotgun: Remington 1187P. Shoots everything, even skeet. 
Rarely gets used, but every time I take it out it just chews through all the loads I throw at it. Probably not as durable as the 870, but shoots fast and recoils less.
This would be a more interesting topic if I could afford more cool stuff
Pistol: Glock 34. I shoot it better than any other pistol I’ve had my hands on so far, and I’m confident in it. Add cheap mags and affordable practice ammo and you’ve got a winner.
Rifle: My mutt AR – BCM Mid-length upper on a RRA lower. Surefire foreend, Aimpoint in a LT mount. It’s my only suitable fighting rifle, really so it’s a default winner.
Shotgun: Remington 870 Express Mag. 20" vent rib barrel, extended tube. Long enough to shoot birds or skeet with, but short enough to be handy. Effective on 2-legged game as long as you stay within it’s limitations. Again, my only shotgun so it’s gets the choice by default.
Pistol: Springer Mil-Spec. It’s reliable as my old G17, it’ll eat anything, and I shoot better with it.
Rifle: Currently an AK-74. Ammo is cheap, the 5.45 is a nice flat shooting round, and…it’s an AK.
Shotgun: Remington 870. It’s an 870, it’s reliable, it’s nothing special…and it costs me virtually no money b/c it’s not an AR or an AK
Pistol: 1911-Custom Caspian.
It’s a .45 ACP 1911, T-box at 25 is almost easy. It may require a bit more love than my Glocks, but I can always find another Glock.
Rifle: LMT 16"
I can take it to most states, it’s damn near DMR accurate with the right glass, it integrates perfectly with my kit. I have sufficient knowledge and supplies to keep it running for longer than I will be.
Shotgun: Rem 870
It works. Whether removing door hinges or dispatching wounded critters on roadways, I know it capabilities and limitations.
Pistol: SIG 226 9mm / .40 S&W. Know the manipulation and have the most rounds and training hours. CCW: 3 226 9mm, 2 .40 S&W.
Rifle/Carbine: Colt LE6920. It’s a Colt. Many training hours / rounds with Colt M4s.
Shotgun: 870P. Federal low-recoil 00 buck with FLITECONTROL wad: tight groups and the wife can shoot it.
edit: 1st pic is my stamped carbon steel slide old school P226 9mm date code KF (1995), 2nd: P226R .40 S&W
Pistol: Springfield PRO, my most accurate pistol and probably the nicest gun I own.
Carbine: 6920 with pretty accessories, because it’s better than my other AR’s so far
Shotgun: rem 870 marine magnum, my first gun.
Edit: pics later.
Pistol: My G19 because it’s stone reliable and can easily be concealed. Parts and accessories are readily available.
Rifle: Arsenal Inc SLR-107CR after I get it SBR’d and the barrel cut down. It’s powerful and compact and reliable to a fault.
Shotgun: I don’t own one.
PISTOL:
Ed Brown Kobra w/maxiwell: The first (of 5) Ed Brown’s I bought, butter smooth, dead nuts accurate, done several pistol classes with, 100% reliable and I love the look of a well work blued gun. Not the most expensive one in my collection, but my sentimental favorite.
RIFLE: TIE (sorry):
DSA Stainless Para-Tactical FAL: Stainless FAL, Trigger job, Folding Stock, 16" fluted Badger barrel, sub MOA…need I say more.
PATHETIC PIC, BETTER ONE COMING!:
CUSTOM AR SBR: Spikes forged lower, LMT LPK, Timney skeleton trigger group, G&R built upper: Noveske 10.5" barrel & Gas Block, LaRue mounted Aimpoint M4, Stubby-LaRue mounted TangoDown, Troy FDE BUIS, LMT BCG, Gas Buster CH, SurefireMB556k, MagPul CTR, MIAD, rail covers…waiting for my FA556 SureFire suppressor to finish off this build. This is my first SBR and Silencer and hence has a special place in my (sick) heart 
SHOTGUN:
Benelli M1Super90: My first shotgun…best gas system on the market (at least it was), never failed me, massive firepower at hand (esp. with factory mag extension), simple ghost rings with tritium, TacStar side saddle & SureFire fore-end.
Glock 19. What M4arc said.
Winchester Model 54 in .30-30. Other “modern” long guns may come and go, but this 80-year-old bolt-action stays.
Mossberg 500 12ga. Simple – and solitary.
Pistol: Glock 21, it has ran for unknown amount of rounds and has never hiccuped. It fits my hand, and I have lots of mags for it.
Rifle: Weatherby 375H&H Weathermark, accurate, light, short rifle that can take care of about anything on this continent, and it is a pussy cat to shoot.
Shotgun: Remington 870 it always goes bang
…
pistol: GSP (Gunsite Service Pistol) - does everything I need it to do with as few bells & whistles as possible. It is my “one & only” gun that I would keep if I could have only one weapon.
carbine: Colt 6920. This is my first AR, and I’ve only had it 2-3 months. Currently it has a DD Omega rail system, and MIAD grip. It will eventually have a thumb-activated light, perhaps a VFG, an Aimpoint (M3 or M4), and a BUIS. This should take care of the area that the GSP can’t cover.
shotty: Following a posterior vitreous detachment and subsequent retinal tear, followed by laser reattachment surgery - I’ve had to give up all “high recoil” weaponry (hence my recent entry into the field of ARs:) Prior to all of that happening - Ithaca model 37. Simple - reliable - and amazingly accurate with both 00 and slugs!!!
Pistol:
1917 DWM Artillery Luger
Amazing pistol, handles well and doubles as a carbine for close quarters combat. Sights go out really far, but I have only fired it at about 30 feet. The only draw back is the relatively low powered 9mm Luger round, but alas they do not make these in .40 S&W. I just need to get my hands on a snail drum and I am set!
Rifle
1861 Springfield Rifle Musket (Reproduction by Armi Sport)
Pretty accurate considering it’s crude sights. There is absolutely no denying what a 58 caliber soft lead projectile will do to flesh and bone. The sights are marked out to 500 yards, but the furthest I have shot it is 100. I love shooting this weapon. The recoil is a gentle push and it isn’t too noisy. I use a 500 grain Minie ball sitting atop 60 grains of FFG Goex (Simulating original combat loading). I make my own 500 grain 99.997% pure lead Minie Balls, and then use Crisco shortening as a lubricant to keep the fouling to a minimum. The original lubricant is mixture of beeswax and tallow, but for me I use Crisco. It’s a hobby all unto it’s own. Plus the bayonet looks sweet .
Shotgun
Browning Auto 5
A true classic shotgun if there ever was one. This one is chambered for 12 gauge 2 3/4 chambering and is fitted with adjustable rifle sights.
Glock G23
Colt LE 6921
18" Remington 870 Magnum with tacticool stock
1911 in .45ACP because it is what I have over 100,000 rounds of experience with and, is “2nd Nature” for me to operate, always goes “bang”, and is a proven man stopper.
LMT MRP AR15, 16" w/ Aimpoint Comp M3, and SF Scout light with VLTOR MODSTOCK, MIAD etc… This is my primary weapon of choice, it is proven 100% reliable, and with various loadings it provides SD protection as well as hunting small to mid-size game. Oh…and it also goes “bang” every time.
Remington M870 w/ 18" IC Rifle Sighted barrel, and a 28" Vent Rib barrel with choke tubes. It has a Youth size stock for quick handling, a Vang 2 shot extension, a Vang Safety, a 4 shot Side Saddle, and a DD receiver mount for a single point sling. All mods. are designed for ease of handling, and versatility. I can us this a a SD piece, hunting deer with slugs, or any type of upland and water fowl. And one more time…it goes “bang” every time!
IF I could add a 4th, it would be my M700 Scout Rifle with 18" barrel, scout scope, BU Ghost Ring sights, Ching sling and cold comfort cheek piece ammo carrier. This would be my preferred “Stand Off” weapon in .30 Cal., but the AR and Shotty could be a close 2nd for this utilitarian function.
Glock 21C with Surefire X300
Colt 6933
Benelli M4
Pistol … lightly modded Colt because it’s a 1911 AND a Colt.
Shotgun … Ithaca Model 37 Featherlight because it’s put many a dove in the crock pot.
Rifle … Stag 152T because it’s more versatile that the Remington Nylon 66.
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I wasn’t going to reply because I misread the premise up front. But this isn’t a “What’s a must-have” thread, it’s what’s irreplaceable. Now that’s a good question.
Honestly, I shouldn’t list anything. Sentimental attachments to guns are lame. And I’m not a collector, so all of my stuff should have equal value in my eyes. But it doesn’t.
So for the pistol it’s easy: my RRA “Adco” 1911 that I bought from you, Shivan. Getting another 1911 that performed as well would take far too long due to my impatience, and it would likely run 200-500 dollars more than this one did. I don’t think I can really justify spending so much on one 1911 when M&P 45’s are sitting there for 450 and change, or Glock 19’s for 400.
For the rifle, I have no answer. I think they’re all replaceable and I’m quite proud of that.
Shotgun…well I only have one. And I have no plans on giving it up. I love my Benelli M1 Super 90 and it loves me back.
toddackerman! The masses insist you tell us more about that Scouty 700! A Scout in .308 is near the top of my short “Must get” list.