This is a favorite episode of mine, not just for the season but for the series, for all sorts of reasons (although I wonder if, when I finally get to watch "Last of the Time Lords," if that won't become my new favorite; I'll have to wait and see). We get answers on why the Doctor left Jack behind, answers as to how Jack managed to get from the year 200100 to 21st century Cardiff, and we have that fabulous, fabulous Matchstick Scene* between the Doctor and Jack when Jack's twisting the canisters into place. I love the fact that it gives the two of them a chance to arrive towards at least the beginnings of some kind of understanding between them for the Doctor leaving Jack behind (I don't think Jack _likes_ the reason for it, but I think he somewhat _understands_ it; and Vinity, I like your point about even the TARDIS's rejection of Jack pointing to the idea that, while the Doctor leaving Jack behind still isn't entirely _excusable_, it is at least _understandable_) -- and, for his part, Jack seems to regain a little shot of hope. I
love it when the Doctor asks him if he wants to die, and he tries to avoid the question, but then he says, "I thought I did. I don't know. But this lot -- you see them out here, surviving, and it's fan
tastic." Between the sentiment, and his use of the Ninth Doctor's catchphrase, I was quite definitely tearing up ...
But I also _love_:
"Wh-ut're you taking your clothes off for?!"
"I'm goin' in!"
"Wuhl -- but the radiation doesn't affect clothing, only flesh."
"Yeah! I look good, though."
Oh, I laugh every _single_ time I think of that line ...
I would also like to add that I
really hope the Confidential for this one is included in the USA DVDs, because I would like to hear about John Barrowman singing on set!

He has to be so _fun_ to work with, because I get the feeling that he so utterly loves his work that _he's_ always having fun, which is the best kind of person to work with in any profession!
* If you are not sure what I am talking about, you need to watch Eddie Izzard's "Dressed to Kill."