Are there examples (current or historical) of commercial aircraft seating arrangments beyond the standard today? Excluding various first-class seating arrangements, are there any examples in history or today, of an airline that has implemented a non-standard seating arrangement?

For instance, most military transport aircraft contain just rows with passengers' shoulders inline with the bow and aft. Are there any examples of where a commercial airline has tried this arrangement -or any other type?

An extreme example would be an airline like a subway car (everyone standing up, just hanging on to something).
Some of the old flying boats had a seemingly haphazard arrangement




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But maybe all flying boat passengers were effectively first class?