Ok. Well after some googling (which takes awhile on my slow dial up internet 
), I found this study. States that there are roughly 111 million US households in 2006, which doesn't include college campuses, institutions, and other "group quaters" it seems. I feel that the number of these types of households is small, and most likely wouldn't increase the number of consoles per household, simply because I bet many college kids (the ones most likely to own a console) would use the console at school and at home).
I also found this study, which states that about 41.1% of US households own a console that connects to a TV (so the DS and PSP are not included). Assuming that the number of households own one of those "mini-consoles" from Froggy that usually only have 1 or 2 games, and are mostly learning games anyway, is negligible (.1%), then we can assume 41% of US households actually own a video game console. The study runs from Q4 of 2004 to Q4 of 2006.
So by combining the studies, we can estimate there are roughly 45.5 million households with consoles in them.
Finally, using this study, we can break down the percentages of ownership a bit. It says 40% (44.4 million) of US households own a gaming device, but that includes PC, console, or handheld device. It then goes on to say 89% (39.5 million) of those gamers game on a video game console, and 23% (10.2 million) own all three. It then goes on to state that 57% of gamers own a PS2, 39% own an Xbox, and 27% own a GameCube, with 8% owning all three. Now it depends on what these percentages are of.
I'm assuming the percents are of the percent of gamers/households with a console (the 89%, or 39.5 million), then the number of households with a PS2, Xbox, and GC, and all three, are as follows: 22.5 million, 15.4 million, 10.6 million, and 3.16 million, respectively. If you add PS2, Xbox, and GC together, then subtract the number with all three, you get 45.3 million users with a console, but only 39.5 million households. So that means 5.8 million, or 14.6%, of households also own 2 consoles. That would mean about 9 million, or 22.8%, of households in the USA own more than one console, which seems to agree with your findings.
*Extended Thought Edit*
If one uses the first two studies to determine the # of households that own a console (45.5 million), then the numbers are a bit different. PS2, Xbox, GC, and all three numbers: 25.9 million, 17.7 million, 12.3 million, and 3.64 million. Since the Xbox only sold 15 million in the America's total, this doesn't work very well (though neither does the first one). Adding the three together and subtracting the all three ownership, you get 52.3 million, so there are 6.8 million (14.9%) households with 2 consoles in them, for a total of 22.9% (the percents would be the same) or households in the USA own more than 1 console.
The problem may be that the # of households that I am using is too large. Perhaps they were using 2004 data, which states there were only 109 million households, or even older data (as both numbers are greater than your 95 million household number).
If anyone finds a problem with my logic, let me know. It's late, so my reasoning skills aren't 100%.
Here are some other interesting things I found:
Google answers with a lot of good info (and sources to back it up!).
