U Under The Cloth - when you look at a tray of things and then someone puts a cloth over it and you have to see how many things that were there that you can remember
W Wordsearch - find words horizontally, vertically and diagonally in a grid of seemingly random letters. Popular across all age groups.
Also a different W - mentioned Wordwheel previously as being similar to the word-making puzzle, Polygon
Y Y-cube. Wooden block stacking 3-dimensional puzzle that you build up to make a perfect cube. I have seen it, but haven't tried it out . The pieces are sort of Y-shaped (ie branched). Looks quite difficult to solve!