Ludisia discolor, the Jewel Orchid, has beautiful foliage; it's one of the few orchids not primarily grown for its flowers. The leaves are usually green with red stripes or veins, though they vary a fair amount. Its flowers are nice, too: it produces sprays of small white flowers. They come from Burma, Indonesia, and Malaysia., and are terrestrial orchids. Ludisia discolor nigrescens is a variety with darker-colored foliage, and Ludisia discolor alba lacks the red pigment, so you get green leaves with light-green-to-silver veins. Both of these varieties are popular, too.
Ludisias like the temperature to be in the intermediate-to-warm range (70-80°F during the day (21-29C), with a nighttime drop of 10-15°F (6-8C)). If it's comfortable for you, it's probably comfortable for these plants, too.
Humidity
Try for about 70% humidity, but 50% is enough if that's all you can manage. You should be able to get by with even less, if necessary; they're fairly robust.
Light
They do best with intermediate light, about 2000 footcandles, more than Phalaenopsis light, but less light than you'd use for a Cattleya orchid. They are better at tolerating low light than too much light. An east window often works well, or a somewhat-shaded south window in the northern hemisphere.
