TWRoO on 23 January 2009
Using the fiscal reports.... as of September 2008 (if you wait a week we can have them as of December 2008)
Wii - 6.65
PS3 - 6.83
DS - 5.39
PSP - 3.91 (not accurate due to mixing of production and retail shipments)
For the X360, we don't have the same data, the best is what they release with the fiscals which was as of September an 8.1 attach ratio according to NPD USA.... but the USA attach ratio is higher than the world average in general so the real ratio will be lower.
For instance the Wii attach ratio in America by shipments is 8.05... so the X360 worldwide attach ratio is likely similar/slightly above the PS3s
