Often an accusation leveled at us tassers is that anyone could do what we do if they just had the time or inclination. Perhaps for even a majority of the movies on the site, this is true, but there are a few contributors who set the bar so high with standards so exacting that when you try to imitate their performance, you find out how difficult it really is to make a good movie.
Bisqwit, Nitsuja, aqfaq, FractalFusion and others who combine intimate knowledge of the inner workings of games to create their own tools and models are perfect examples of this.
Among the human-only players, Phil especially continually surprised us and stood out as an exemplar of skill. Anyone who has tried to improve the games he has touched can only agree. For me, The Legend of Zelda specifically comes to mind. Almost all of the people that have seen Phil's run probably don't really understand how insanely difficult and frustrating that game truly is. My own limited foray into LoZ:2Q certainly opened my eyes to what a monumental undertaking Phil's run was, and cemented it in my mind as the finest run on the site.