Let me start off by saying that after watching this episode for the first time on DVD at 10 o'clock P.M. one night, I could not fall asleep until about 3:00 A.M.
This brief review may contain spoilers.
I'm a long-time fan of The Sopranos and I can safely say this is the best episode I've seen. I'm not saying everyone should feel this way, but I do. This episode is identical to the weekend I spent with my family, watching over my own father, comatose in the ICU before he passed.
The episode begins with Tony in an alternate reality: he is a salesman who's identity has been mistaken for that of a man named Kevin Finnerty.
By the time ten minutes had gone by, I knew either Tony was dreaming, or I was watching some other show. It wasn't like the normal Sopranos and I loved it.
Option 1 is confirmed when Anthony (or "Kevin") looks into the sky at a "helicopter spotlight" and we see prodding through it, a doctor with a flashlight. We see this only for a moment and the sequence plays out until we go back to real life in a situation similar to the one I just stated.
Tony has come out of the coma for only a moment. His boys take A.J. home and Carmella, overcome by stress, breaks down in the hallway: a signature moment in the episode.
For the remainder of the episode, we cut in between the real world: the family dealing with the potential negative outcome of this coma, and Tony's alternate reality, which parallels what's going on both in his mind and in the real world around him.
Then comes the stellar point in the episode: after A.J. finishes telling his mother he's flunked school, she walks in to see Meadow sitting at Anthony's side.
She approaches Tony, and utters the best line of the episode: "Anthony, can you hear us?" In Tony's world, he enters a dark hotel room and turns on a light. He takes off his shoes and goes to the phone. He tries to dial, but he cannot--as if he were trying to say something back to Carmella, but couldn't physically bring himself to do so. Not yet.
He sits down and looks out his window. A shimmering light that has reoccurred throughout the episode now seems to call to him from the other side of the city.
"When It's Cold I'd Like To Die" by Moby marries perfectly with these last images and helps in creating an emotional roller-coaster of an episode.
10 out of 10.
P.S.: Watch the next episode. You find out what the light is. It's wonderful.

Regarded by many critics as one of the biggest stinkers of all time (certainly the biggest stinker of director Brian De Palma's career).
Sherman McCoy (Tom Hanks) is a smug rich boy whose life goes to pieces when he and his lover Maria Ruskin (Melanie Griffith) are involved in a hit-and-run. His story is chronicled by another smug guy, reporter Peter Fallow (Bruce Willis).
Well, as I said in my summary...
What is this movie supposed to be? It seems to combine comedy, drama, and satire, but it sure doesn't add up to much. It's undermined by unimaginably loathsome, one-dimensional characters who you'd never want to have the displeasure of meeting in real life.
I'm no big fan of the novel (I started reading it once, but couldn't finish it because it wasn't to my liking) but it's obvious to me that those who did / do enjoy the novel consider this film to be a complete travesty.
I've never seen so many talented actors strive to hard to give a below-average movie some semblance of quality and fail. What a waste.
The problems start with casting nice guy Tom Hanks in a role that is clearly supposed to be UNsympathetic. And the role of Peter Fallow in the novel was that of a Brit. Bruce Willis is badly, BADLY miscast in the role. What was the thinking there.
Alas, not even Morgan Freeman can escape the film with his dignity intact, being obliged to deliver a lame, heavy-handed lecture on 'decency' after the climax.
This movie ends up turning into an absurd farce.
I liked the assemblage of talent; for that I will give it four out of ten, but I'm sure some people will say a MUCH better movie could have been made from the source material.