All consoles suffer from this - i.e. the actual install base is sure to be less than the sold to consumers figures estimated here. Now, a fair bit is down to replacing broken units, but other factors come into play - people double dipping by trading in old consoles (still working) for new ones for example.
Yes, the 360 probably suffers from it the most, even with the extended warranty of the RROD period - statistically it has to as it had by far the highest fail rate plus I believe it also featured the most double dipping, particularly around the launch of the 360s.
But the PS3 isn't immune to this, I know people who bought Slim's to replace older models via trade in - in fact I just traded in my old PS3 recently for a Slim. So the PS3 has seen double dipping, too. It will also have seen people replacing failed units as well - the PS3 fails too, just less often.
This is a touching subject though, so I'd tread with care. Nothing wrong with raising it as it's as valid as this own sites attempts to guesstimate the actual Move install base from the pieces sold, but it's an emotive area.
Personally, I think the 360 has been affected less than you'd imagine from RROD (due to the warranty covering a lot of the replacements) but probably more than the avid 360 fans would like nonetheless.
The Wii I doubt is affected by this much at all. There have been no console revisions so no reason to double dip and the console's failure rate is tiny. But the PS3 and 360 will have install bases below the actual figures on this site, and yes the 360 probably has the highest percentage difference.
Try to be reasonable... its easier than you think...
