For being such a short, fun, funny little thing ... it actually made me cry. There was such affection in DT's eyes when he told PD, "You were *my* Doctor ..." That one moment somehow managed to sum up the way in which "Doctor Who" resonates so deeply with its fans. I loved it!
And oh, the conversations were just marvelous. _Marvelous_!
"Not a lot of men can carry off a decorative vegetable."
"And it would help, it would _really_ help, if there wasn't some skinny idiot ranting in my face about every single thing that happens to be IN FRONT OF HIM!"
"Ah. Okay. Sorry ... Doc-tor."
... and may I point out the joyfulness of the "no beard, but a wife" joke, which I did not get the first time round?

EDIT: Oh, and I found this on IMDB:
"David Tennant wrote the speech where the Tenth Doctor explains the characteristics he inherited from the Fifth Doctor and tells him that he loved being him. He included the line 'You were my Doctor', because Davison was Tennant's favorite Doctor when Tennant was growing up."
Does anyone know if that's true? If it is, it's fan*tas*tic.