agree with the op that it's a bit plastic and identikit to pick Sweet Caroline like every other sporting event.
OTOH you need something anthemic with a catchy chorus that everyone can sing along to, so it has to be a fairly middle of the road choice, whatever they play.
Thinking off the top of my head 'Itchycoo Park' by the Small Faces ('it's all too beautiful...') would have a similar effect while being (a bit) more original, but I bet there's someone else already using it.
There are probably others that fit the criteria too, but again, if it's a well-known singable tune there's a good chance we'll be inadvertently copying another club