You can see this list just tries to dig into sensation. The fact that they put Fallout 3 [after it only being out like a week] on it and NOT Fallout 1/2, is telling. Fallout 3 is good, but not better than Fallout 1/2 ....how it suddenly gets up there is just to tie in with popularity.
Besides why put "Ultima Series" there, and then have Final Fantasy XI/VIII, Baldur's Gate 2, Diablo 2 , Oblivion split up?
If he was consistent he would'be put there "Elder Scrolls Series" [Daggerfall was still groundbreaking back in the day] . "Diablo Series" [Diablo 1 was also pretty much groundbreaking] and of course "Fallout Series" and "Final Fantasy Series" .
PS: Ultima 9 was epic fail anyway (which is why there is no last Ultima)