Xbox 360 Wireless Controllers currently on offer at £22.99 instead of £29.99, whilst this isn't a massive saving it's a decent price and there's plenty of stock around.
Both black and white are available at this price (link is for the black version).
Catalogue numbers are:
Black - 568/5334
White - 567/9261
They also have a compatible charge and play kit on offer at £6.99 too, again both colours are available.