Was in Tesco Extra, Ipswich today and aswell as some DS and wii games on the 2 for £30 offer that has been mentioned before they had some titles on 'buy one get one free'. Titles in this branch were:
Cooking Mama 2
I did it mum (boy)
I did it mum (girl)
Maths made easy
Fashion designer (not sure on exact title)
all were £19.71 but the shelves were in a bit of a mess so there may well be other titles included that had missing shelf edge labels - if your branch has different titles feel free to add them below!!
They also had Mario Party DS and Yoshi's Island DS at £23 each which didn't seem too bad for an instore price.