No, as far as I can tell they'd still be considered a creature. Technically speaking, corpses are considered objects that were formerly creatures and would thus be valid targets for the "single object" version of the spell, but an unconscious creature is just a creature under the unconscious condition. Being carried doesn't change that, so they still wouldn't be a willing creature.

Quote from Jo_Schway >>

Unconscious creatures are not considered "willing", as they cannot consciously allow the spell to be cast upon them. Obviously you can house rule otherwise, if it better suits your game, but under normal circumstances they wouldn't be a valid target for the spell.

 This is why you have all your party members sign pre-emptive consent forms for all your high level utility spells.

I don't believe by any means this is RAW or RAI, but as a DM I rule that the default state is always willing. It takes an active decision to resist a spell. I usually describe that decision (when the players don't know what spell is being cast) as "some magic begins to pull at you, do you resist it?" My players know that sometimes allowing magic to happen can be beneficial and they will find out more, or it can get them killed. But it presents the situation so that not doing anything means the effect happens. Unconscious creatures are willing because they don't have the capacity to resist.

Of course, this opens up the possibility of your PCs getting abducted and isolated by nefarious monsters or villains. It's not necessarily a win for the players to rule that way. But I think it is more interesting.

So this spell states, "This spell instantly transports you and up to eight willing creatures of your choice that you can see within range." Does that mean all targets must be willing, including yourself? Could you, teleport a group and not go with them?

Could you use Teleport to travel to a moon or another planet since it is a place that you can see?

Very familiar" is a place you have been very often, a place you have carefully studied, or **a place you can see when you cast the spell.**

Yes you see it, teleport to the moon with no mishaps.

No, you can't just teleport others with this. The exact wording is that it transports you and other valid targets of your choice. Additional riders are optional, but yourself are not.

so basically you just need to picture the location in you head

What would happen if you have been away from your home for 50 years, it is obviously a place you are very familiar with, but someone knocked it down and built a different structure with all different layout inside and out?  Could you still arrive in the living room if the living room no longer exists?

You cannot teleport to your destroyed family home. As per the spell description, "'False destination' is a place that doesn't exist. Perhaps you tried to scry an enemy's sanctum but instead viewed an illusion, or you are attempting to teleport to a familiar location that no longer exists."

I agree. Plus, with a familiar place, you have a 75% chance of getting there anyway, and with literally anything associated with the area, you're guaranteed to succeed. I don' think it's unbalanced or unfair at all. Even still, this spell is only situational anyway.

Homebrew Idea:

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the number of creatures or objects you can teleport increases to 16 creatures or 2 objects at 8th level, and 24 creatures or 3 objects at 9th level. Additionally, at 8th level you have have the option to remain behind, and at 9th level the teleport is also always On Target.

Quote from TheRhinoDude >>

Homebrew Idea:

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the number of creatures or objects you can teleport increases to 16 creatures or 2 objects at 8th level, and 24 creatures or 3 objects at 9th level. Additionally, at 8th level you have have the option to remain behind, and at 9th level the teleport is also always On Target.

 The 9th level would need a caveat regarding a False destination, since you couldn't be On Target to a place that doesn't exist.

Poor DMs whose players get teleport and has to prepare the WHOLE ENTIRE WORLD!! "Let's switch to once-a-month sessions, guys."

Could someone maybe, teleport to the moon?

The Astral Adventurer's Guide lists teleport as a means of travelling between worlds in the same Wildspace system, so yes, unless your homebrew says that different celestial bodies have a distinct planar existence. Whether you can survive on the moon will also depend on what world you are on.

Better hope you’re not off target, or end up in Wildspace 

Quote from timothyrem >>

Quote from TheRhinoDude >>

Homebrew Idea:

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the number of creatures or objects you can teleport increases to 16 creatures or 2 objects at 8th level, and 24 creatures or 3 objects at 9th level. Additionally, at 8th level you have have the option to remain behind, and at 9th level the teleport is also always On Target.

 The 9th level would need a caveat regarding a False destination, since you couldn't be On Target to a place that doesn't exist.

 Just have the wording be "at 9th level treat any roll to determine success a 100"
so for false destination it would always get "Similar Area"

Associated object:

Does this mean I can be in possession of an item that belonged to someone/someplace and use that to teleport to that person or place with 100% accuracy?

Quote from thundergod118 >>

What about an unwilling creature?

 Maybe a saving throw? Some other spells do that.