FLYBOYJ pretty much said; approximately 95% of the aircraft flying these days are made out of aircraft-grade aluminun alloy, with the other 5% made up of wood, stainless steel,titanium and various composites. Titanium was very popular in the '60's and '70's for the construction of exotic, high-performance aircraft, like the SR-71, but it was very difficult to manufacture back then. Nowadays, most high-performance aircraft (F-22, F-35, Eurofighter, etc.) use a lot of composite materials, like carbon-fiber, thermoset resins, and thermoplastics.