"I love everything about Green Giant arborvitaes but I'm afraid anything over about 35 feet could fall in a hurricane and GGs can get about 50 feet tall."

On good sites they can definitely keep going.

No [quality] plant grows to 30 ft. and just stops.

That being said, I strongly advocate hollies in the role you are describing.

1) SOME (but not all) do tend to grow quickly to maybe 20' and slow down, but of course they don't stop

2) unlike conifers, they can be "rebooted" by cutting to the ground, if absolutely necessary for some reason. In that case you would have been extremely vigilant for a few years to have them grow back as attractive single stemmed specimens. I prefer Eurasian hybrids or Fosters, but the native I. opaca is perfectly serviceable as well.

https://www.houzz.com/discussions/4977109/we-agree-some-cutting-grown-trees-need-aggressive-waterspout-control

I would stay away from Alaska Cedars especially if you ARE NOT on pinelands sandy soil; although not a problem for now, I would wonder if they will eventually suffer the disease issues that lawson cypresses have on the east coast.

The so-called "Murray Cypress" of US commerce, actually C. X ovensii, is probably one of the best conifer options. Assuming you find someone selling the real thing and not some derp re-labeling leyland cypress.

This same question has been presented and addressed in at least 2 other threads. But the responses were summarily dismissed. If chosen well and carefully sited and planted, conifers are not any more subject to windthrow than any other tree. And there ARE many cultivars of conifers that will grow slowly enough to remain under the OP's height restrictions for many years.....decades even. Probably longer than the OP will own the property or even be alive. The correct way to evaluate their potential is by rate of growth and IMO, the American Conifer Society is one of the few sources that will provide accurate data in that regard.

The holly suggestions provided by david are an excellent alternative to a conifer. I omitted hollies in my response as they are not as common on the west coast as they are on the east and in many cases, pose an invasive threat here.

I like hollies, there's 3 ~12 footers in the front that are maintained, but I plan on just leaving the trees be, and whoever lives here later might not like the sharp leaves and might remove them which I don't want to happen. And I don't want the sharp leaves to drop over fences too much even though all it really needs is to be mowed over on a low'ish height and they should mulch right up and not be a problem.

Unfortunately, a shorter ~30 ft tree doesn't mean it won't fall or break from catching more wind like a larger tree, it's just less of a problem if it does, and thus hopefully something new gets put in its place, old roots removed and all.

can see the stem of this ~30 ft blue spruce? snap and break,

unfortunately most evergreens which I want are softwoods

https://youtu.be/pBkPichBlt8?t=838

this shows how small and weakly rooted (in certain but likely many soils) the root system of a large seemingly strong healthy tree can actually be, especially when ground is saturated:

https://www.youtube.com/watch?v=NMwCThoK43k

someone mentioned a lot of trees won't just reach a certain height and stop growing even if it's commonly noted as the max height. In perfect conditions in nature where a tree happens to find exactly what it likes it can grow much more than max heights noted, this nootka cypress weeping alaskan cedar says can grow 90 ft in perfect conditions, not 30' like commonly noted for home landscapes but if you conditions are perfect for that tree then it can grow much taller.

https://www.youtube.com/watch?v=t3ITdkSZ7BM

I'm not going to argue with anyone's choice of trees and whether or not they fear them falling on anything. I'd suggest they go live on the Great Plains, though: no grasses out in Kansas will ever crush any structure.

That said: beware youtube videos which just show pictures/events, and give you no other context - if you are not well-versed in what you see. I suspect that large tree went over like it did not just because of Hurricane Sandy or saturated soils. I'd bet dimes to doughnuts that the tree's mature root system was truncated/damaged by home construction or utility excavation, which severely reduced its capability of being anchored during stressful events like strong winds.

THAT said: I'd suggest considering a Sweetbay Magnolia (Magnolia virginiana), and maybe an evergreen form like 'Tensaw'. These make up into very nice dense plants with the added bonus of lemony fragrant showy flowers in June. They would have absolutely no problem with wetter conditions, and should fit all your other requirements.

Here is one in 2010:

Here is the same plant in 2016:

just learned about Junior Giant arborvitae , maxes around 20 ft, prefer 30 or 35 but might go with these, cheap and won't cost several thousands to plant almost a 200 foot run of whatever I decide on. I do have a few green giants in the outer corners I'm keeping though and hopefully they don't get near like 50-60ft ever.

However, this 2022 drought heatwave, arborvitaes were some of the only few trees I saw really harmed, lots of established mature ~8 year emerald greens fully brown and dead and some ~5 year green giants browned pretty bad. Rhododendron saw died even in shade but might sprout new growth. Some dwarf alberta spruces not near their 40 year lifespan saw died and something like a burning bush saw basically a whole parking lot mature landscape fully browned out.

I'm installing a permanent drip irrigation to these trees so drought shouldn't be a problem but I just hope it's actually used later on.

Green arrow nootka max around 35 ft but would need a ton of them since they're so slender to make a full row.

Still researching but getting ready to plant soon.

Check out cryptomerias.

"a 200 foot run of whatever I decide on."

Is there some real reason you want a row of the same thing as opposed to a mixed border?

If and when you lose something 10 years down the road you'll want to be able to fill the hole with something that fits in and matches reasonably. In a mixed border you can use anything, but with a monoculture you'll be out searching for 13.5' specimens of xxx to fit.

"I'm installing a permanent drip irrigation to these trees so drought shouldn't be a problem"

Do NOT rely on drip irrigation to get your trees established.

They'll need deep watering that has been confirmed to penetrate to full root depth.

Since yew toxicity and deer eating them were mentioned, I wondered whether deer were somehow immune. Perhaps not - here's a link with a story on Japanese yew killing deer, elk and pronghorn.

maxes around 20 ft

This occurrence does not exist - a tree that is no longer growing taller at all is dead or dying back. Even the world's tallest trees grow taller every year. Or die back periodically at the very top, start over (when not able to keep the entire top hydrated to the very tip during dry years).

So, your 20 ft. option will probably become your 30 ft. choice once enough time passes.

Otherwise if you are wanting a tall hedge because you are planning to plant near the houses you don't want to see whatever you choose is going to take many years to grow as tall as these buildings. Whereas if you planted screening or added built features like a trellis near where you are looking from instead you could get a lot of relief almost immediately. Without the effort and expense of a 200 ft. planting. Same as putting blinds on a window instead of erecting a tall fence, trellis or wall along a property line.