I was in my local Woolworths today (Sutton, Surrey) and they are clearing out their remaining stocks of Xbox games. About 40 titles that I saw, from £1.99. The most expensive were £9.99.
Titles that I remember :- Crash Burnout, Lego Star Wars I, Super Monkey Ball, Star Wars:Revenge of the Sith, Gun, Doom, Doom 3, Need for Speed:Most Wanted, SSX World Tour, King Kong.
Please note, I've checked another store (Morden,Surrey) and they aren't selling any Xbox games at all.