Dvd.co.uk are selling "Dragonball Z: Budokai Tenkaichi 3" for the Nintendo Wii for £15.99 (inc Del)
You can get cashback through the usual sites (e.g. 4% Quico, making it just £15.35)
The next best price seems to be £18.99 from SoftUK.
Also available as part of their 2 games for £30 deal. :-)
The Ultimate DBZ Budokai Tenkaichi Game!
-More than 160 characters and over 30 unique battle stages!
-Unlimited gameplay through 10 different game modes recreating the complete Dragon Ball world!
-For the first time ever, battle against your friends online!
-New Battle Replay Mode to save and replay your favourite fights!