The G650, now in development from an all-new design, extends the venerable Gulfstream line with even more range and a bigger cabin. With a top speed of 704 mph, the G650 strives to take the fastest-civil-airplane honor away from Cessna’s Citation X. The cabin is more than six feet high and eight feet wide, with big 28-inch windows—eight on each side—and a maximum cabin altitude of 4,850 feet. The first G650 flew in November 2009, and deliveries are expected to start in 2012. If you want one, get in line—Gulfstream says it has 200 orders in hand.