All right, so you've just discovered the level of my sense of humour and the depths to which I will sink, but anyway, don't think I've linked to these two yet.
(All Ages, Six & Peri)
The Doctor decides that it's about time Peri learned more about him. Naturally, this involves a slide show presentation, some confusion and a written test.
TTR: Bric a Brac
(All Ages, Nine, Crossover with The Two Ronnies).
Which involves one Doctor, two Ronnies and a sonic screwdriver and surprisingly little innuendo.
I've removed the obvious TTR links in this one, but it actually takes place in Nameless, because where else would you find Nyder and Nine shopping at the Two Ronnies' hardware store?
( Some explanation (you may need it) )