Official Xbox 360 Wireless Controller | £19.98 | Zavvi
Now that Microsoft are actually taking Games With Gold seriously, the Xbox 360 is perhaps a stronger choice than it's ever been before. If you're looking for an extra controller for a spot of co-op funtimes, Zavvi have the official black Xbox 360 pad for under £20. It's still quite possibly one of the most comfortable controllers of all time (possibly second only to the Gamecube's in that regard), and a spare pad is always handy for impromptu game nights.
Thanks to BuzzDuraband at HotUkDeals.