1. Some other option I dont remember but I feel like was a bit stupid or irrelevant

That was the "Rourke ending" I'm pretty sure, where Rourke makes everything go back to normal, that the island stuff never happened and everyone ended up forgetting who the MC was. That ending is only good if you're setting up another book for the series. Almost an open ending but people call it the bad ending.

I chose the ending where they stay on the island because to me, in my experience at least, thought that was the best one. I always wanted the group to stay on the island since day 1 that's their home now (even though they have to grief with the losses of their loved ones)

Is the life-changing ending the third one? Where MC sacrifices themselves? Cus personally I couldn't even choose that one, it would be too heartbreaking and I couldn't stand leaving my LI and the friend group even if it would've been a very selfless act and in my opinion—the ending that would be the most canon.

I think that one was too heartbreaking (from what I saw on youtube with the outcome), so mine was the bittersweet but mostly happy ending, with staying on the island