Two choropleth map projects I've wanted to make for a while:

https://housepricedashboard.co.uk - shows a visualisation of house prices in England and Wales since the 90s, with filters for house types, real vs nominal, and change views over time

https://councilatlas.co.uk - similar structure to the above, but focusing on local council datasets. The idea is to make it easier to compare your local council's performance against the rest of the country.