Name any decent Wii title that we may have forgotten to buy

[TWRoO]

Battalion Wars 2.
F1 2009 is an awesome racing game even if you don't like F1.
You don't have Metroid Prime 3,I would suggest going for the trilogy (it's the only platinum rated game on the Nintendo channel)
No More Heroes
Okami

And Endless ocean if you think you might like that sort of thing.

You should be able to find many of those cheap now (well Metroid Trilogy is probably going to remain full price, and F1 2009 is still high priced here in the UK... ah you are from the UK, well I got it for £30 from Sainsburys)

Also these are good, but not worth a high price IMO, but you can probblay find them less than £10 if you check CEX or shop online:

Deadly Creatures
Geometry Wars Galaxies