Right now I would have to vote for the Canton duo. Their teams dominate ice dance, and V/M & D/W are two of the best teams I have ever seen. Obviously Igor and Marina are doing something right.
I, too, vote for the Canton duo. They single handedly built the "golden age" of the North American ice dance. Their contribution in that sense is similar to what Yao Bin has done to the Chinese pair skating. Unlike Yao, though, the talent pool of top notch ice dancers in N. America is deep. This has a lot to do with their style of teaching - fostering collegeal, rather than competitive, attitude among dancers.
I kept thinking how serene and relaxed were Marina and Igor's facial expressions during the 2011 worlds, in contrast to Zhulin's tense and unyielding facial expressions. One may say that it would be easy to be relaxed when their pupils have done so well. I would rather think it is the otherway around.
Z/S's students have done well over time presicely becuase Z/S brought supportive and accepting attitudes.
John Nicks. He was more successful as a pairs coach, but had a lot of phenoms with the single ladies- like Sasha & NNN. It was too bad consistency was not their forte, but I loved their style and John's attention to detail was one of the compounding forces behind their artistry.
Tamara Moskvina is great. I love the fact that she puts so much humanity (don't know how to write it better) in her work as coach. She seems to demand her male students to be polite and to treat the girls well and I really appreciate that. Just look at Artur Dmitriev, Sikharulidze and Smirnov. Apparently she wants her students not only to be good atheletes but also nice persons. For me thats a very important thing in sport. Moskvina also helped Berezhnaya off the ice when she was going through bad times.
Carlo Fassi was one of the best, if not the best figure skating coach of all time. Not only did he coach Peggy Fleming, Dorothy Hamill, and Robin Cousins to their Olympic gold medals, but he also coached many other elite figure skaters such as Jill Trenary. Fassi was a master school figures instructor, and since figures were a major part of competitions until 1991, his coaching was very instrumental in guiding the above skaters to their medals. Just my two cents, of course.