Most pre-order Wii games are 32.99 from HMV.co.uk with FREE DELIVERY. Card is not debited is not taken until shipped.
Use the £5 off £30 shop voucher as detailed in other posts here to bring price down to £27.99. It may be better if you are ordereing more than one to use the 15% off voucer - there are loads of HMV vouchers out there at the mo so check them out!!!
Go though Quidco for 11% back (3.08)
Hey Presto (most) Wii games are now £24.91.
Also can get nice deals on £40 pre-order XBOX 360 Games (like Tony Hawks for 31.15).
Remember these are all offical UK PAL games (not like the ones from Playasia etc which is cheaper).