Khvostov 7G-02

Low DPS, range, clip size. Few upgrades.

I am a big fan of Vision of Confluence, solar scout rifle. It has an automatic fire upgrade, increased damage to oracle upgrade, and solar damage is just a bonus. It's my dream gun.

Poor stability makes it not very useful at range, but it is good at short range. Pretty much all missed shots get returned, though if the round hits a phalanx's shield or the forcefield on a hyrdra it doesn't seem to get returned.
The lack of range and stability makes it poor for most strike bosses, but it works quite well at short range crowd control. Just don't expect to get a lot of head shots.
I haven't gotten into the crucible much lately so I don't know how good it is at PvP, but you're probably better off with a gun with more reach in most cases.

Just my 2 cents.

Crypt Dweller SR1- Not a great Scout Rifle. Too slow and heavy.

This was the first Legendary weapon I got and I still like it very much. I've fully upgraded it and given it to my Titan in favour of using a more powerful Scout Rifle that I like less on my Hunter.

My CD SR1 has options including +2 agility or super-quick scoping. The other upgrades aren't that great (bonus accuracy while crouched and kills reduce grenade cooldown) but I love the Red Dot-ORS on it: big viewing area, and super-precise.

Invective- 4 Shot mag is a drag, and ammo regen is too slow to make up for it. You are better off with a solar Comedian.

Really depends on the situation. Will it be enough to cut through a swarm of Hive Thralls? NO.
But will it lay the smackdown on a Cabal Centurion? Sure. Can it save you thousands on Special Ammo Synths by letting it recharge in your back pocket while you use another weapon? Yep.

If you've got time (or your Special Ammo Synths are still on cooldown) it's great. Sometimes I use it to supply ammo for another special weapon - especially on missions where 'Juggler' is active.

The Swarm - With the magazine upgrade and extra ammo carrying capacity, big hard hitting very stable arc weapon that kills everything. Feels less like a machine gun, more like a AA cannon.

Proxima Centauri II - Bloom-less Reach DMR. Lightning fast reloads after precision kills. Love this rifle with the ACOG scope.

Invective - Regenerating ammo plus range, solar damage, and auto fire when you need it. BOOM STICK.

Hex Caster - Basically agree with Cody - mows stuff down at close to medium range but kicks like a bronco and useless at range. Proxima stole me away from it pretty quick.

The first three are my current loadout, and I'm digging it. Can handle any situation at any range.

Thorn - agree with Cody. Picked it up from exotic bounty because my other option was Terribad Juju or Invective. Would have gone with invective but I have a legendary shotgun that works fine, and Thorn will be buffed.

The Supremacy - legendary Queen sniper. I have this in void and arc flavors. With perfect balance and the ambush scope it's great in Crucible for those snappy MLG 420 head shots. The near death reload/speed buff is negligible. Sometimes useful if you just barely survive a sniper duel.

The Crash - FWC shotgun. Good rate of Fire lets you outpace other shotguns in Crucible, so I bust it out when I'm faced with teams of slide-shot gunning hunters, or playing skirmish on maps like Anomaly. Oversized rounds make it cause a screen shake effect on your targets so it's easy to disorient people if you start firing before you're in lethal range, which is very short. I expect this gun to still be solid after shotguns get range nerfed, since it has short range already.

Gjallarhorn - nothing special in crucible. If you have the mini-rocket upgrade it's nice for taking down yellow mobs or large groups in strikes.

Zombie Apocalypse WF47 - legendary Crucible MG. Amazing stability with upgrades and decent impact. Absolutely demolishes Guardians, and picks up two mags worth of ammo on a heavy weapon drop, as opposed to the one that Swarm gets. Since MGs benefit from precision damage and it's incredibly stable, you can jump in a Titan bubble for a damage buff and put heavy precision damage down with minimal effort in PvE.

The Swarm - Not a big fan. Got this after Zombie Apocalypse, so I find it too kick too hard in spite of its admirable impact rating. Also, it has a smaller max ammo cap and only gets one magazine per heavy ammo drop.

Universal Remote (exotic shotgun): I haven't seen anyone post this one yet. It's basically what you think - if you like running around with shotguns all the time, this one's for you. The accuracy/crit damage boost probably isn't as extreme as you're hoping when you first see it. You won't be picking off enemies from a mile away. But it is enough to quick-scope and 1-shot most smaller enemies within 30-40 feet or so. You'll become very dangerous at short range with this thing, if that's your style. You do have to think about the fact that you're now using a primary with limited range, though, and pack a special that can make up for it if you're going to need range - sniper or a stable fusion rifle. Overall, worth it if you're an up-close player.

Bad Juju (exotic pulse rifle): Agree with Cody for now, and I am likewise keeping mine until the buff hits. Its special effect could make it beastly in theory, if its base damage or magazine were increased to the point that it could reliably kill enemies with less than 1 magazine.

Stranger's Rifle (rare pulse rifle): Again, I find myself agreeing with Cody. Seems like a lot of people are down on this weapon, or just had something better already, but I used it for quite a while after I got it, even maxed out its upgrades. And as a general rule I'm not big on pulse rifles.

The Devil You Know (legendary hand cannon): I decided to post mostly to let people know about this one. I've seen several people mention that, like me, they got a lot of use out of the Regulator rare hand cannon, and this one's a great replacement if you want something similar. It doesn't have quite the impact of the Regulator, but it's close, and I think it handles pretty much identically. Has the same enormous magazine (or cylinder? whatever).

Grim Citizen III (legendary auto rifle): Auto rifles aren't my thing, but this one's OK. Stability is excellent, easy to keep rounds on target. I don't care for the life support upgrade on mine, but the handling's good in general and there are probably more useful upgrades out there.

LIGHT/Beware (legendary fusion rifle): Good impact and stability. Mine is solar damage and eats Wizards for breakfast. One of my favorite weapons, if only because of my history with it. It was my first legendary (purchased it from Vanguard Quartermaster), and at the time the most challenging thing in Destiny for me and my squad were the Hive Wizards in strikes (this was before the update that eased up on majors in the later minion waves). This thing tipped the balance in our favor.

The Calming (legendary fusion rifle): Good fusion rifle. Mine happens to be arc damage. It also has one upgrade I really like (kills grant bonus reserve ammo) and one I find mostly useless on a fusion rifle (slide further). There are probably units out there with a better second upgrade.

Super Good Advice (exotic machine gun): It does have some recoil, but its special effect mostly negates it, and I've found it does much higher damage per shot than most fast-firing machine guns. I found it OK against most strike bosses, especially Phogoth and Askor. Not great against Valus, though, because his crit spot is so small and you usually have to be too far from him to hit it reliably. However, as Durandal117 noted, it is excellent for crowd control so I still bring it to that fight to deal with minions. Lastly, I'll note that this thing is good for a laugh when demonstrating the special effect to others. Get a full magazine, and just fire at nothing until it runs out. You'll be there a while. I need to test and get some actual numbers, but I feel like the rate of return on missed shots is somewhere between 75-90%. Definitely significant. Lastly, the exotic bounty to get this one is far and away the easiest exotic bounty I've had. All you have to do is kill enemies with a machine gun - there's no crucible required at all. You have to wait for Xur, but I was lucky enough to get this one on a Saturday. :)

Unfriendly Giant (legendary rocket launcher): Nothing super-special about mine, but it's a two-shot launcher and reloads quickly if you get a kill with the last shot (not hard to do with a rocket launcher, obviously), which makes it the best solar launcher I've found.

My contribution to the list - I have it fully upgraded.

Truth - Awesome void-damage rocket launcher. Warheads aggressively track targets (when ADS) - I've cross-mapped moving people on First-light and Bastion with this. Two warheads in the tube. Upgraded for near-max velocity and near-max blast radius.

Video example of the range at which tracking rockets can work

Video example of rocket curve/tracking

This gun is amazing.