I won't pretend to be an expert on the various MLS supporters have displayed over the years, but I have to imagine that Saturday's nine-parter from ECS has to be among the most impressive. Best? I'll let people that pay a lot more attention to that than me make that call. That Mario Bros.-inspired one that the Chicago Fire's Section 8 did last year was pretty cool (although I still don't get the relevance). Timbers Army's display during their MLS home opener was very impressive.
As far as the Tifo we've seen from Sounders supporters, I don't think there's any question that a new standard has been set. This one really had everything. It paid homage to every era of professional soccer in Seattle. It was boastful without being overly arrogant (at least from my admittedly biased perspective). But best of all, was the final sheet which featured a grinning Roger Levesque and the words "48 seconds," which really put it over the top.