As a Brit it's interesting seeing 11 or 12 (depending on how you class Fleetwod Mac) of the top 15 albums are British/Irish. I gave some thought as to how the list would work out if you carried out a similar survey in Britain with a similarly weighted list of responders...so I'm thinking overwhelmingly male, and white people aged say 30-60 over-represented, but there will obviously be plenty of other sampling biases at play eg response bias as people who take music seriously are clearly more likely to respond.
The main thing I'd say is, i think there would be fewer of the prog rock types...don't get me wrong I think Dark Side Of the Moon would still be top 10, but probably the only Floyd one that high, because I think culturally the punk thing over here probably had a more lasting and profound negative effect on the popularity of the big 1970s behemoths such as Floyd, Led Zep etc.
So I think if you did a similar survey over here, you'd probably get a similar number of British bands in the top 20, but certainly the first two Oasis LPs, possibly the first 2 Joy Division LPs, and at least 1 Smiths LP (probably The Queen is Dead) would be in there.