After passing the $200 million domestic box office milestone earlier this week, Guardians of the Galaxy became the top grossing movie released this summer over the weekend.The Marvel Phase Two adventure, directed by James Gunn, has earned $251.8 million at the domestic box office in just four weeks, which is more than enough to surpass Michael Bay's Transformers: Age of Extinction, which was previously the top summer 2014 movie with $243.3 million.