leading
adjective [ before noun ]
uk/ˈliːdɪŋ/ usbest, most important, or most successful:
a leading brand/brand name The cereal is sold under several leading brand names.
a leading business/company/firm Investors can buy shares in many of the world's leading companies in other parts of the world.
a leading producer/provider/supplier The software has helped the company become the world's leading producer of kit airplanes.