whats the best quest in this game?

[muted for doing ur mom]

uh like best reward and loot, i havent played this for awhile lol

[Corona Varus]

Come Fly With Me has the most loot during the early game. You can sell what items dropped from the corpse in that area.

[Vex Hilarius]

A lot of quests are there to add to the story and lore, that is the reward, besides obvious XP and/or caps. If you're questing for tangible rewards you're not going to have a good time. Take probably what's considered the best quest in the game, Beyond the Beef. There's no unique weapon or armor you get by completing it, other than whatever stuff you find in the casino.

Unique loot is more commonly found around the map not as quest rewards, there's a few but it's a relatively small chunk of the quest pool.

But to answer your question, probably Bleed Me Dry because you get a unique shotgun and a night with Red Lucy. Good combo. A runner up would probably be For Auld Lang Syne for the remnant armor and power armor training

[pswynnave]

"Best loot" (if you're speaking of caps) is a little irrelevant unless you're playing with some kind of economy overhaul mod, it's very hard not to be rich in this game, especially if you pick up Jury Rigging & weaponize it against every traveling merchant. Easiest early-game caps (besides high-luck gambling) imo is the wrecked caravan east of Vegas, I reckon all the Van Graff combat armor you can loot is worth 6k+ caps.
Do note the "discounted" merchants you can sell items at full value to, such as the BoS quartermaster or Cliff Briscoe.
The other suggestions were solid, I'll make my own suggestion of Black Mountain's "Crazy, Crazy, Crazy". If you can take down the super mutants & nightkin, their drops alone are a significant financial windfall. Otherwise, the stealth boys you would get along the way from Come Fly With Me & Joe Cobb are sufficient. Plus you can get Raul, need I say very nice to have around.

[Knux Redbeard]

If you're running heavy armor, and want power armor, then doing the full Brotherhood Of Steel quest line and getting power armor training is pretty good. I've not been able to complete For Auld Lang Syne as early in a playthrough, and the remnants power armor degrades very quickly compared to T-51 power armor. You also get an excellent merchant to sell stuff to if you go the BoS route.

The Great Khans are an excellent faction to buy ammo from. Making friends with them is worth it even though none of the quests pay much.

Once you've got the Anti-materiel Rifle and a mag of explosive rounds, make enemies with the legion as soon as possible. You can take out the entire hit squad with one round if you land a sneak attack critical on one of the dudes in the center. This generates so much loot so regularly that fencing it becomes a problem.

Ratslayer is an excellent gun. No quest, just go get it.

The Boomers quest line gets you access to the best supply of repair kits in the game.

[Thermal Lance]

That moment when you say "Hello" to Benny and turn the casino into a blender.

[Facetable]

Midnight Science Fiction Double Feature!

technically amazing in terms of rewards as you instantly get

-poison immunity
-unbreakable head and torso
+1 strength
-reduced chance of addiction
-access to a player home which you can later teleport to at any time even when overencumbered
-And more!

(Also I like it for the RHPS reference)