One of my favorites is the dendrobium (sometimes called the Thai restaurant orchid, reflecting the way many of us are familiar with it). In nature it is found in the Himalayas, Southeast Asia, Japan, Malaysia and the Pacific Islands. As you can see in the pictures, they can be recognized by the prominent 'chin'. Because they come from diverse climates, and require conditions similar to 'home', they are somewhat harder to grow.
Vandas are very popular due to their fragrance and bright colors, and have the distinction of being almost the only orchids with bright blue flowers. They come from East and Southeast Asia, New Guinea and the Pacific Islands. They typically live in trees and in in greenhouses are often suspended in wooden baskets which give their roots access to moisture and nutrients from the air. They like to be in warm, humid settings, with bright light, and hence are often more suited for greenhouse conditions. The drama of their colors, and their long-lasting flowers make it worth the effort.