ShopTo are selling "The Simpsons Game" for the Nintendo Wii for £19.99 (ind Del)
You can get cashback through the usual sites (e.g. 5% Quidco, making it just £19.19)
The next best price seems to be £23.71 from Amazon.
Homer, Marge, Bart, and Lisa use exciting, all-new powers to save the world from rising chaos. To help the Simpsons, gamers at home must journey through all of Springfield (as well as vast worlds beyond!), vanquish an amazing array of villains, and fight their way through parodies of multiple popular games.