They have a cornetto in every film. In Shaun of the Dead he got Ed a strawberry one, red for blood and gore: zombies. In Hot Fuzz he got Danny an original one, blue for the police force. In The Worlds End, Peter sees a mint choc-chip wrapper fly past, green for aliens ^.^
Sounds just about right. Shame that in Worlds End that they didn't eat one, just showed the wrapper. Also another occurring theme is that arcade game that was in Shaun of the Dead. Sound of the machine can be heard in Hot Fuzz and Worlds End.