If you had to choose, which game seems more goofy and cartoony? BG2 -- with its focus on alignment or DOS2 which doesn't have an alignment system? My answer is DOS by a mile.
I think DnD lives in some place on a continuum between the cartoony world of DOS1 and the realpolitik of Westeros. I love the Ice and Fire novels but I want to play an RPG in Faerun.
DOS2, but not by a mile, it would be by a mile if there was no alignment in BG2. I enjoyed DOS2, but I would also enjoy it more if it was more serious,I enjoyed BG2 as well even with alignment. But like I said alignment is not tied in my mind to the setting, it doesn't suddenly become westeros without it.