Mine too (that is, we had to sing it, not that it was my favourite (or indeed "favourite" - I didn't really mind it. (These brackets are getting out of hand)))- also 'Little Boxes', 'The Ink Is Black' and (less politically) 'Puppet On A String'. And for singing when not in Assembly (e.g. sort of music lesson-y things or singing to parents), 'Yesterday', 'When I'm 64' and 'Obladi Oblada'.