The Gulfstream G150 (912.965.3000, www.gulfstream.com) has set world speed records for flights between a number of city pairs, including a recent trip between Savannah, Ga., and Seawell, Barbados. That 2,000-mile flight took 3 hours and 54 minutes. The aircraft has a normal cruise speed of 495 mph and a range of nearly 3,500 miles. The G150, which is priced at $15.7 million, also can climb to its initial cruising altitude of 41,000 feet in just 25 minutes. It burns just 220 gallons of fuel per hour, making it the most fuel-efficient jet in this category. The cabin seats a maximum of eight passengers in a large, quiet space that is 5 feet 9 inches wide and just as tall.