I think for the Michael Jackson album, "Off the Wall" should also be accepted, since at 8x Platinum (US), it can certainly also be considered "best-selling".
as of today it is about 8x in the US but about 20x platinum worldwide. however it is not best selling as his top album has sold 33x platinum worldwide.
Yeah, upon further reflection (unless the wording was changed), it does reasonably read as "THE album that sold the best", as opposed to "A best-seller", but if they are really that similar in worldwide sales (double digit multiples of Platinum on both? I had no idea), I can see someone else nitpicking it. But I hereby withdraw my own nits :-)