Top 10 Hypothetical Roller Coasters

This would be an excellent and fantastic ride for thrill seekers to be built.
I thought of this in 2018.

Riders would go on the trains and wear these special spacesuits, the familiar safety spiel we all know of in Space Mountain would be said and then they would go through some hills, turns and a huge drop into the main lift, slowly going up.
A countdown is heard starting from T-10 seconds, and then they are launched into space (literally) in just a few seconds.

The rocket train would pass by the Moon and the other planets, then the stars and through a short wormhole, and then leave the Milky Way and twist their way past other galaxies.
They keep accelerating, making sharp turns, acrobatic maneuvers, and sudden drops, and don't slow down until they reach the edge.

Then they see a weird dim glow, meaning they reached the edge of the known universe (13,700,000,000 light years), in 1 minute.
Then they make a huge 90°-banked 180° turn back to Earth(and slow down the whole time), passing the galaxies and going through a long wormhole back to Earth in just 30 seconds.
They hit a long brake run and and go through a tunnel and slow down, until they come to a complete stop.

These days, so many people want thrills at Disney World and Disneyland, and they're meant to be places for the whole family, and not everybody's up for thrills (health warnings, height requirements, seating restraints, acrophobia, claustrophobia, lift hills, launches, inversions, g-forces), so if Disney made this, then the guests would learn their lesson of whether or not thrills are suitable for the parks.
It should be either an overhaul of Magic Kingdom's Space Mountain (since right now it's already rough and outdated), or a new one in Shanghai Disneyland (since they don't have one, but might need their own).

A popular hypothetical concept of a roller coaster designed to kill its riders.
It's 510 meters tall and the riders then go down a 500 meter drop approaching speeds of up to 223.69362920545813 mph (360 km/h) and go through 7 loops, each loop being smaller than the last to keep the g-forces going up to 10, which will cause cerebral hypoxia(lack of sufficient oxygen in the brain), leading to death.

It would be the perfect ride for criminals to get a death sentence as well as people who want to be euthanized.

There are many amusement park companies, but the one capable of doing such a thing (and so many other things) is Disney.
It would be built in a remote field at Walt Disney World and be a hit.

It would be a huge and fast roller coaster located in Orange County Florida with launches, hills and turns.

The 1st one would start the ride and riders would go through hills and turns, even inversions, and go underground and through buildings such as the OCCC, and nearby roads, and then they would be launched into the stratosphere, before freefalling back down to earth, with tractor beams to get the vehicles landing in the right place.
I thought of that concept in 2016 and it would be a great one.

It would knock the socks off of every thrill seeker.

It was a concept built in Roller Coaster Tycoon where riders would spiral down the track and slow down the whole time.
The whole trip would take 210 days and riders would die from starvation(though a man, Prahlad Jani, was claimed to have survived more than 78 years without food), making this the 2nd type of euthanasia coaster.

It would be built in Orlando Skyplex, and be the 1st Polercoaster.
It would be 570' making it the tallest roller coaster in the world, and it would have 7 inversions including raven turns, and have the steepest drop, at 123°.
The top speed will only be 65 mph, but that won't keep it from being extremely thrilling.

There would be no over the shoulder restraints(just lap bars) to prevent obstructing the view.

It's planned to hold 1,000 riders per hour.
Design permits and long planning have delayed it several times, and if it's made, it'll make history in amusement parks as the 1st polercoaster in the world, and after that, more polercoasters are planned on being built in other parts of the world.

It would be a virtual reality roller coaster (like SeaWorld's Kraken Unleashed) built at Universal parks.
During the main lift, the scenery on the vr movie would be about riding E.T.'s magical bike up into the air, but once you make it down those turns and drops, the bike flight becomes out-of-control chaos.
Twisting over the land, will you land back safely, or are you gonna Crash?
Find Out.

It would include a slow lift up, and then fly over the park and go through long corkscrews.
It would be built at Seuss Landing at Universal Orlando.

Based on the scene in the adaptation of Dr. Seuss How the Grinch Stole Christmas.
It would delight Dr. Seuss Grinch fans and thrill seekers.

It would be a bobsled coaster at Seuss Landing in Universal Orlando.
It involves riding on a train that looks like his sleigh with a giant Christmas bag on top, they go through a very slow lift and then the riders would spiral and twist and turn their way to the bottom of Mt. Crumpit, just like in the story of the Grinch.

If there were a ride at a Six Flags Park or at Movie World in Australia, this would be a good coaster.
It would be a virtual reality ride(like Kraken Unleashed at SeaWorld Orlando) and the footage in the vr goggles would be about flying over Pandora.
The roller coaster would simulate riding on top of a Banshee.
I know Disney made their Avatar ride, but that's a simulator and not a roller coaster, meaning this ride would be a good idea at the mentioned parks on here.

A Sonic-themed coaster at Super Nintendo World at Universal parks where riders go through the worlds Sonic traveled through.

The vehicle carts would be shaped like Sonic the hedgehog, giving riders an idea of what hitching a ride on Sonic would be like.

It would start out with a launch (to simulate Sonic's acceleration) and go through lots of twists, turns, and inversions, just like Sonic's maneuvers.

There would be different levels and each would also include portals.

Alternatively, it could've been a VR coaster, but nowadays, practical immersion's a better idea (including props such as the golden rings).

It would be Universal's fastest coaster, beating out the Velocicoaster, given Sonic's speed.

Plus it would be the first non-mouse coaster to use single vehicle carts at a time, which would be a problem for wait times (leading to virtual queues instead of physical lines), but that's a fitting thing given the Sonic theme.

You can't have a train made up of hedgehogs.

It's an individual coaster meaning the "cars" are not connected together. The "cars" are shaped like Nyan the cat and you piggy back on them and are launched into the track while the "cars" give off rainbow backlighting like Nyan Cat's rainbow trail. The soundtrack is Nyan Cat's theme song.

It would have been the least articulate idea I could think of. Think about it: 1,000 feet high with construction crew and equipment building this beast for half a decade. It's no higher than the Empire State Building in New York City. How many twists and turns are there? Will it be a mile long? Who knows where it'll be built? Anyways, it may happen in the future or not.

Like Kraken Unleashed, E.T.'s Thrilling Flight, and Avatar Flight of the Banshee, Star Wars Spaceflight would be a VR coaster where riders wear VR goggles and scenes in space and in Star Wars worlds would show.

It would include battles and combine those with thrills.

Unlike Hyperspace Mountain in Disneyland Paris, this includes VR and shows additional scenes and stories, yet takes you on a new adventure with each ride(kinda like said Star Tours but better).

The track dives down a deep hole and riders would go down it, never knowing how far they'll go down until the track levels out at the bottom.
Then there's a huge lift hill, making riders think there's going to be another drop, but instead it's just to the unloading area.
It's inspired by Alice falling down the rabbit hole into Wonderland.

It would be just like in the episode.
You would be launched from 0 to 60 mph in 3 seconds toward the main lift hill (which's 500' tall by the way) and go down the big drop at 200 mph, leading to twists and turns through the "tri-state city" while a Doofenshmirtz animatronic points its laser toward the tracks.
Riders would be thrown off the track into random landmarks depending on the trajectory. Landmarks like Mt. Rushmore, the Statue of Liberty, the Eiffel Tower are great examples.
They might or might not get tossed into a plane or a tree.
They get flung to space after bouncing off of a landmark at hundreds to thousands of miles per hour.
This leads to the big drop, a plunge back into Earth through its atmosphere (which would send the vehicle in flames from atmospheric friction) before landing back into the tri-state area through a vertical brake run that levels out into the unloading area.
It would be built in a city known as the tri-state area either built by the Walt Disney company or within a currently-existing city the tri-state with a tri-state Disney park installed.

You go up the hill and into a long helix in a way that mimics the movement of something being flushed down the toilet.
Water would spray its riders to create the feeling of being splashed in toilet water as you're being "flushed". The track is surrounded by a giant toilet shaped structure for theming. After the helix, you pass through a long tunnel (representing the pipe into the sewers) which would be smelly (like sewer) and once you leave the "pipe", you go back into the loading/unloading area.