I can't say which is my favorite interview because there are so many good moments in all the ones I've seen.
One I saw from the 70's where the interviewer from the "Swap Shop" had some really cute things in it such as:
The interviewer freaking himself out about Tom's "Doctor Who stare."
I thought he was going to run away giggling for a moment, lol. And Tom was very obliging to give him a good one.
Also I thought it was very sweet and gentlemanly of him to ask the callers to talk to Liz Sladen. He actually set his phone down so that her time with the caller was more private for her. I thought it was cute how he played with his scarf when she was on the phone with the caller. He even went so far as to switch his body position away from her to give her more privacy. Before that he was leaning in towards Liz and they both had their legs crossed towards one another. I got the feeling that Liz was helping Tom be more comfortable in the interview. Only a guess. But they did work with one another so maybe it was mutual comforting, lol.
On of the questions regarding the length of Tom's scarf Tom proposed sending in a postcard with a guess of how long the scarf is and whoever guessed correctly would get a scarf from Tom. I wonder how many scarves he had to send out? lol
Whenever I watch an interview that was done before Tom's book, "Who on Earth is Tom Baker" came out I can't help but notice how he answers some of the questions. For example, When an interviewer would ask him about what he was doing before he got the Doctor Who part. Tom would talk about working for the construction company or having done some other shows but since I have read the book I just go "WOW"! Tom amazes me he really does.