The Holy Terror
is fantastic. The sixth Doctor, Frobisher, and a spooky medieval castle.
I love Time of the Daleks
. "The Daleks revere Shakespeare!"
Speaking of Shakespeare, The Kingmaker
is riotous. A drunk fifth Doctor, Shakespeare, Richard III (who sounds remarkably like Christopher Eccleston), Peri and Erimem, a robot, and Jon Culshaw's Tom Baker impression.
I like Sympathy for the Devil
a lot. David Warner plays the third Doctor, only he arrives on Earth thirty years after he was supposed to be exiled. Mark Gatiss plays the Master. And David Tennant is in it as well as a UNIT colonel.
For road trips, Shada
works really well. I like the Big Finish Shada
a lot; McGann and Ward have a really good rapport.