I have just had a play on the Thomas the Tank Engine website:

http://www.thomasandfriends.com/usa/Thomas.mvc/Games/Home


There are lots of different games with different ability ratings: easy, medium and difficult.  There are memory games, matching games and in the difficult section there is a great emotions teaching game.  I also enjoyed the 'build an engine game'.  You have to drag the different parts of the engine with your mouse to make a complete engine.  These games would be really useful teaching aids and would be really motivating, especially as many of our children love Thomas.