I like David Chow's work the most personally in the listing, but Amano has had the most impact. I'm not sure why John placed me up there with Oliver and Amano, dang. Also, I do not do this full time(1-2 days a week, tops), all of the people above do it full time. It is their primary job/profession.
Given I've never once entered a single competition in any contest, ever.
You did not list a single Dutch NBAT scaper.
Perhaps this was an oversight? Do you know their aesthetics and rules?
It helps to understand some of what I do and why.
George Farmer and the UK group have really become quite good in a brief period of time. CAU are all very very good.
Pasquale from Italy I like a good deal.
Also, the highest ranking ADA contest tank was George Lo's 20th rank from the USA. AFA has consistently good aquascapes. Both they and ADG are ADA trained however. I like Oliver, he's a funny guy. Taiwan and Viet styles are emerging somewhat also.
I think ADG wins for being able to keep the full spectra of aquatic animal livestock and scapes from virtually any genre: reef, paludariums, freshwater, biotope, ADA style, etc. Not one of the other people on the list can make that claim.