In my opinion, Kinda is the deepest, most imaginative and thought provoking story in the history of Dr Who. The Mara is certainly the scariest and most disturbing monster ever seen, and there is a wonderful exploration of madness and crumbling personalities in the characters of Hindle (an outstanding performance from Simon Rouse) and Sanders (veteran actor Richard Todd). Janet Fielding gives easily her best performace as the possessed Tegan, the scenes set inside her mind are eerie and haunting, the music and sound effects are very atmospheric and the dialogue is wonderful. Kinda is a real gem of a story, working on many levels and I believe one of the greatest Dr Who stories ever made.
The sequel Snakedance is almost as good, but tries to be a bit more "normal" so doesn't quite have the same depth as Kinda. The mythology of the Mara is explored well, the sets and effects are pretty good and the performances excellent (Janet Fielding again shines and young Martin Clunes makes a particularly good villain). It's still a very clever story but Kinda was so unusual and thought-provokingly imaginative that it's inevitable it's sequel would seem less impressive. I would still say it's the third best Davison story after Kinda and Caves of Androzani and one of the best of the 80's.
A superb double bill of Dr Who, and an essential purchase just for the wonderful Kinda.