My favourite and favourite at past RJams and when used in class has been "Forcefield" by Elton Lane. Page 60.
Ben Davies' Sonic Pi and Minecraft codes have always looked awesome but I have never had time to try out. That is changing at up coming Minecraft Raspberry Jam and Leamington Raspberry Jam.
This would not have been as varied and rich in content without the community around the Raspberry Pi circuit. At last count it is over 200 pages long so it has lots of useful stuff in it KS 2/3 /4 appropriate. Feel free to have a play :)
P.s. credit where credit is due if I had not read about this half finished book by Craig Richardson then well this wouldn't exist :)
link to his unfinished book https://arghbox.wordpress.com/2014/04/25/minecraft-pi-recipe-cards/
Link to his complete and very useful book to buy: https://www.amazon.co.uk/Learn-Program-Minecraft-Craig-Richardson/dp/1593276702
Furthermore 50-60% of my ideas usually stem from something that I have seen here:
or in this : http://www.stuffaboutcode.com/p/minecraft.html