I have spotted some flaws and omissions already, even on the updated list. (The benefits of having seen and heard every TV story transmitted.)
Some of the comments make interesting reading:
The North Sea gas seaweed monster in "Fury from the Deep" was the scariest of all the Doctor Who creatures, for me.
At the time, in 1968 when this was aired, Britain was converting from town gas, to natural gas from the North Sea, so this was a very topical story, and as a 12 year-old, it all seemed so much closer to home, so much more real, and more likely than beings from outer space.
The creature came out of the plumbing, and gassed people, before taking them over and transforming them into seaweed monsters, themselves.
Bonnie Langford appears to have been missed off the list.