The 2 Biggest Bughouse Tournaments in the U.S. are: U.S. Open Bughouse and U.S. Amateur Team East (USATE) Bughouse held yearly in Parsippany, New Jersey.  There are many more Bughouse tournaments,  however none of them compare to the intensity and strength of the players that compete in those 2.  Bughouse tournaments exist at various state Grade & Collegiate Championships (Texas obviously being the largest), smaller informal ones, but once again for the best quality Bughouse, expect to find them at the above 2 aforementioned events.  WORLD OPEN in Philadelphia also features Strong Bughouse action,  however no tournament — just hours and hours of free Bughouse fun! :)