As an Irish person, I'm with the Americans on the last one, neither on the Downtown/CBD one, and the Australians on all the rest. I'd say town centre. Had heard of Downtown before (notably in the song), but CBD is new to me. Central Business District, I guess? TRiG.
Well as of his interview on the Pat Mcafee Show yesterday, honestly i'd say he's developing more of the Australian Accent now than in this video. He's starting to lose his Texas twang lol