Dimir Devotion by under_a and Izzet Control by beatnik bobby. Both of these cards take full advantage of two of the strongest cards in the format - Gray Merchant of Asphodel and Treasure Cruise - in a Control shell to eke out a late game win. Interestingly enough, only one card from Fate Reforged made it into these decks, and that was Whisk Away in the Izzet Control build. This is fairly typical in these initial events after the release of a new set, as players acquire cards and try to figure out how best to utilize them in the new metagame.
Outside of these two trophy-winning decks, the Top 8 of both events was split up between three additional Izzet Control builds, 3 other Dimir builds, 3 different Red Deck Wins builds, 2 Esper Control lists, and one entry each of Mono Blue, Orzhov Control, and Jeskai Control. Other than the Red Deck Wins lists, each of these others included either Gray Merchant or Treasure Cruise. The biggest surprise to me was the lack of Boros Heroic and White Weenie placing in either event, since these are two of the other top archetypes in the format right now.
This lends itself to a straightforward analysis: unless you're hyper aggressive, you probably should be playing Gray Merchant or Treasure Cruise, or perhaps both. Mid-range or Control archetypes that don't include either of these cards probably won't consistently win against those that do. Furthermore, with the increased number of -1 / -1 spells like Barrage of Boulders, Festergloom, and Scouring Sands in both the Sideboard and even maindeck, the metagame is leaning more and more towards Control.
On the other hand, I still want to see a decklist with Temur Battle Rage make Top 8!