QUOTE:
I could almost, almost go with the Leave ending, if it didn't involve Laura. In tacking her on at the end, it becomes a half-assed "...and they all lived happily ever after" cliché.
It's impossible for me to accept that Laura would leave with James, under any circumstances. Whatever connection those two had was permanently severed the moment James confessed to her, and she stepped out of that hotel room. The Leave Ending is very much open to interpretation. All we see is Laura leaving Silent Hill and vanishing into the mist, then James following some distance behind her. All we can presume is that Laura has finished her business in Silent Hill. James, likewise, has finished his. They're moving on with their lives. And within that context, there are three very distinct possibilities:
1.

Laura is still angry with James and has no intention of going anywhere with him. They are leaving in the same direction and at a similar time, but they are not together.
2.

Laura and James are leaving town together. James, out of respect for Mary's memory, will get Laura back to the proper authorities, who will return her home (given the reference to "the sisters", she probably lives in a Catholic-run orphanage or hospital).
3.

Laura and James have made peace, and James intends to adopt her and raise her as his own.
The reason that the third school of thought is so prevalent is that "Leave" appeals most to the people who prefer happy endings. And it's the happiest possibility: James finds redemption, Laura has a family.
What we don't know is what happened to Laura between the time she smacked James and left and the time we see her proceeding ahead of James. It is commonly believed (by me among others) that she saw Mary herself. Mary told her how much she loved her, but also how much James did, and how much her suffering hurt him. They said their good-byes, and Laura was able to reconcile with James. Here's one writer's take on what happened:
viewtopic.php?f=9&t=16275It is also possible that she did not see Mary, but that James found her later, chased her down, and spoke to her on his own. I expect he would have had to hold her still to get her to listen, though, at least at first. If Laura did not see Many, I would say that it's a toss-up between Possibilities 1 and 2. If she did not get the truth from Mary's own mouth, Laura would want nothing more to do with James. She might accept a ride from him because she had no other option, but that's all.
If Laura DID see Mary, then it's between Possibilities 2 and 3. Mary would not want Laura wandering around on her own, that's how little girls wind up in shallow graves. James might merely take Laura to safety. Or, their shared grief and love for Mary might lead to understanding, and eventually affection.
I am personally of the belief that Laura did indeed see Mary, and Mary told her to go with James. However, the two had no real connection, so James merely delivered Laura into the right hands. Then, the two went their seperate ways with some relief. Within the realm of what we see in the Leave ending (and what we know of the characters), it makes the most sense.
Concerning "In Water", I freaking hate that ending. If James wanted to die so darn bad, why struggle, fight all those monsters, even kill Eddie to stay alive? "Maria" is nearly as grim and depressing. Some people like that sort of thing. I don't. I'm the kind of guy wou'd have liked "Romeo and Juliet" much better if the two lovers had connected successfully, slipped off to another town, and had eleven kids together.
As for "Rebirth", I think that whatever happens, it's going to be the worst ending of all. Pagan deities, demons, old gods, whatever you want to call them... they charge a high price for their services.
So even though I don't think James adopts Laura, I am still of the mind that the Leave ending is the best by a long shot. James is emotionally shattered, maybe scarred for life, but he leaves town with his life, sanity, and soul intact. In Slent Hill, that's the best you can hope for.