There were 12 stations in total one for each Underground line. 5 stations are in Zone 1. 6 stations are in Zone 2. One station is in Zone 3. One station is in Zone 5. The additional clue that I didn't give, just to make it harder, is that they are all on interchanges.
Picture 1 - King's Cross St Pancras (guessed correctly most times - 13)
Picture 2 - Elephant & Castle (the sandwich bar was a bit of a give away there - but only 4 people guessed this correctly and there were some wild differences in guesses with this one)
Picture 3 - Finsbury Park - guessed by five people
Picture 4 - Bank - 11 people got this one
Picture 5 - Canada Water - 7 guessed this
Picture 6 - Rayners Lane - guessed by 8 of you
Picture 7 - Farringdon - 9 people got this
Picture 8 - Edgware Road - 7 got this right
Picture 9 - Whitechapel - 8 people guessed correctly
Picture 10 - Finchley Road - only 5 of you got this
Picture 11 - Mile End - guessed by 10 people
Picture 12 - Ealing Common - this was the hardest and only two of you guessed it correctly
No one guessed all twelve correctly but Rich and Chz got 11 stations each (quite an achievement), miles away got 8 and John F got 7.
Many thanks again to IanD for devising the quiz. Great idea and yet pretty difficult to solve.