One of the side effects of going to a family Bar Mitzva out of town is that you unexpectedly end up with a few moments of peace and quiet.
It takes me roughly five minutes to put on a suit and pretend to be a civilized human being (and four minutes of that is practicing a marginally humane facial expression).
My various family members take a little more time to get ready. If I were at home, there would be a million things to do. Since we are out of town, I have a few minutes to kill. I'll be wrapping this up in the airport somewhere I am sure.
A brief perusal of the usual online forums suggests that there are new posters out there significantly confused about the subject of scoping gas guns.
 

Naturally, a lot depends on what you plan to do with the gun.

The type of a gas gun (or really any gun) you choose flows out of what you plan to do with it.

The type of an optic you choose also depends on what you plan to do with the gun.

The type of a gun you choose DOES NOT DIRECTLY DICTATE THE CHOICE OF AN OPTIC.

They are not unrelated, but one is usually not a direct consequence of the other. The gun is obviously a consideration. For example, if I happen to have a firearm with a very short handguard, that limits certain options. Still, aside from the aesthetics, fundamentally, the application drives the choice of the gun and of the optic.

If you want to go fast with it (clear buildings, etc), put a non-magnifying optic on it. I have a Mepro MOR Pro https://alnk.to/eONlVIo on mine. Before that, it has Vortex UH-1 on it. https://alnk.to/dWdz1Eh Both are full-size optics because I am not trying to keep the weight to a minimum. In terms of getting on target quickly, I think holographics to have a slight edge, but MOR Pro has a couple of additional lasers built-in that are valuable for me.

If your astigmatism makes red dots and holographics unusable, there are several excellent 1x prismatics out there https://alnk.to/cwTvnEj

If you are looking to set up a general purpose relatively accurate AR carbine, get an LPVO. This is the scenario where you do not know what you are setting up for, so you need a true generalist. There are many good options out there. I tend to go with relatively light options, so I am rather anxiously awaiting the arrival of the very compact SAI10.
Until then, here are the LPVOs I use. Most of the LPVOs I use on my guns happen to be FFP:
SAI6 1-6x24 https://alnk.to/fwsnRID
PA PLxC 1-8x24 https://alnk.to/8tQ4D66
Vortex Razor Gen3 1-10x24 https://alnk.to/5jmqYqF
Delta Stryker 1-10x28 https://annexdefense.com/optics-and-optic-accessories/delta-optics/

Primary Arms offers their PLxC 1-8x24 with both FFP and SFP reticles. Both are quite good, but up to now, the way the SFP reticle with a bright fiber dot came together was pretty special. FFP version is quite good, mind you, and they have a new one with a nuclear bright diffractive dot that I look forward to testing.

SAI6 is a somewhat unassuming design that works better in real life than you would think it should based on paper specs. That's why I have three of them. My favourite version is the one with mrad tree and high visibility features.

Razor Gen3 with a nuclear bright reticle illumination is truly fast on 1x and I can take it quite far out on higher mags. If you want a 1-10x that is nearly as fast as a red dot on 1x, it is very hard to beat.

Delta Stryker 1-10x28 is more of a DMR scope with side focus and slightly larger objective. It is very capable across the board, but not quite as fast on 1x as the Razor.

They all have their place and they all work. I also have March Shorty 1-8x24 that has been living on my MiniFix pistol in 300Blk. I might migrate it to my 458SOCOM. It has been superceded by the excellent March 1-10x24 Shorty with its dual focal plane reticle and side focus. It is also a truly excellent general purpose scope, but I do not have one on hand and I figured in this case I should talk about the things I do have here. Delta Stryker 1-10x28, while not quite as nice as the March overall is very good and serves as a DMR oriented LPVO for my purposes.

All of the LPVOs I personally use are still over $1k. If you want to be under, get a prismatic with an offset red dot. There is a broad range of prismatics out there and I have talked about them extensively. If you are looking at it as an LPVO alternative, I am partial to the Element 5x30 https://alnk.to/eONlWUi 
In terms of image quality, it will give anything this side of $1200 a run for its money while offering a 30deg AFOV. 
If you pair it with a well-made but inexpensive enclosed red dot like the Gideon Mediator https://alnk.to/hswIIn5 you are pretty nicely set. That is the setup I have on my FoldAR that I use when travelling for different carbine classes. If an offset RDS is your primary 1x optic, you need to practice with it, but it is relatively intuitive.

Next step up the scope size ladder are the MPVOs. Everyone defines them a bit differently and quite a few complain that all of these classifications are an exercise in mental masturbation. On one hand, they do have a point. On the other hand, I like to be able to separate all these options into directly comparable classes. It makes my life as a reviewer a lot simpler.

If you do not have a hard requirement for 1x, but also do not need particularly high magnification, you get an MPVO. That's a scope with 2.5x or less on the low end, objective of 44mm or less and, preferably a FFP Reticle. I also want to see these be of a relatively compact size since they have to work well behind a clip-on. Upper end magnification is not super critical since most of the use will be on 10x or less. You will only dial up (if it goes higher) on rare occasions when you get to shoot prone in good light.

March 1.5-15x42 is probably the purest expression of this idea and I have one. It is a truly flexible design in terms of what you can do with it. https://alnk.to/bEjIhWk

Leupold Mark4HD 2.5-10x42 is excellent and I am making good use of it as well. https://alnk.to/4qME4vC

SWFA SS HD 3-9x42 is the OG of this category. https://swfa.com/collections/swfa-ss/products/swfa-3-9x42-ss-hd-mil-quad-reticle-30mm-tube-1-mil-clicks-ffp

The new Mark 5HD 2-10x30 with CMR-Mil reticle is extremely promising, but it is not here yet. Same for the Steiner H6Xi 2-12x42 with STR Mil reticle.  The MPVO category is, thankfully growing because, as revolutionary as LPVOs were when they came about, not as many people need 1x as they think.

If on a budget and need an MPVO, Swampfox Warhawk 2-10x44 is quite competent, but a little heavy for the category.  Athlon Helos BTR Gen2 2-12x42 is pretty much the standard carrier for a budget MPVO.

Personally, I would want to see more compact options with a 36mm objective and there are some coming.

March is as full featured as it gets. If you truly want to do everything with one scope, this is as close as you are going to get for now. 

Leupold Mark 4HD is a lot less expensive and a lot simpler. There is also a lot less to adjust and it is easier to set up and use. There is something to be said about that. It could use an abbreviated tree reticle of some sort, but even the aging illuminated TMR in mine works well enough. This is also an excellent straightforward hunting scope.

With scopes like these, an offset red dot gives you 1x, albeit with some re-training. Still, one of these scopes is what you setup if close quarter stuff is not in the plans.

Moving up from there are the Crossover designs (various 3-18x50, 3-15x50, 4.5-22x50, etc scopes). That's what you put on a gas gun you want to use when you need to shoot far, but still want to carry this thing around here and there.

I like this scope category and have quite a few of these in varying price ranges.  Some are on accurate semi-autos and some are on bolt guns).
GPO 4-16x50 ultra short (currently tested on a 16" barrel and nicely accurate 6.5 Grendel AR-15)

Burris XTR3i 3.3-18x50 (off the gun for some side-by-side comparisons, but will likely end up on a 22-250 Tikka T3x) https://alnk.to/hDrtPpr
Telson Toxin 3-18x50 (no host gun yet, but an accurate 5.56 AR-15 built around an 18" WOA barrel is the likeliest candidate)
Vortex Razor HD-LHT 4.5-22x50 (currently on a 6.5PRC boltgun set-up for factory NRL Hunter competition) https://alnk.to/gVMrU9R
Leupold Mark 4HD 4.5-18x52 (it has been on a bunch of different guns; not sure what will be the final destination) https://alnk.to/7qlwW73

Delta Stryker 3.5-21x44 (found a home on a 22" 224Valkyrie gas gun for now; technically, this gun can carry a larger optic and it might) https://annexdefense.com/optics-and-optic-accessories/delta-optics/
Tangent Theta TT315M 3-15x50 (spent most of its career with me on an accurate 6.5Grendel, but is currently on a M28-76 Mosin) https://alnk.to/4XwVcHA

There are probably others in the safe I am not thinking of at the moment and there will be a few of the new ones added to the stable later this year. 

 If you've got an accurate small frame AR with a 16" to 20" accurate barrel and you like stretching the range of your gas gun, one of these is your best option.  I happen to like relatively light weight accurate ARs, so with any of the scopes above, I can have a nicely accurate 1000yard capable gas gun that clocks in under 10lbs with a bipod).  I really should continue with the whole "Guns of the Dark Lord" series, now that I think about it.  With the advent of new and exceptionally well-made "small large frame" guns, this category is really alive and well.  

 On up from there are the 5-25x56, 4.5-30x56, 7-35x56, etc full size precision scopes.  That's what you put on an accurate semi-auto that you do not plan to lug around much or at all.

 The latter is not my favourite category.  I have one like this.  It is a large frame AR-10 type gun built around a heavy Dracos 243Win barrel that was an old experiment.  It is around 13lbs before optics.  I am currently using it to finish testing Delta Javelin 4.5-30x56.  I am not carrying this thing anywhere unless there is a real probability that I will need to club someone with this thing.  Then, it is awesome.  The original idea behind that gun was to make a semi-auto long range varminter, so it is a 1-9" twist barrel and I have no intention of walking far with it.  I also have no intention of building anything along these lines again.  If I want a heavy precision gun, it will be a bolt action.

To cap it all off: figure out what you want to do, then set up a gun and optic for it.  Given how many options we have, there is no need to overthink it.  If you want to go fast, get a red dot or similar.  If you want to shoot far from within 50 yards of the truck, get a full size 56mm precision scope.  If you want to hike around and shoot far, get a crossover 50mm design.  If it is a dedicated DMR type, an MPVO with a red dot is your best bet.  If you have no idea what this is for, get the nicest LPVO you can afford.