The Sobralia orchid genus grows ubiquitously in much of South and Central America; I've heard them called "ditchweed"! They have beautiful, short-lived flowers whose appearance is somewhat similar to a large Cattleya orchid. Flowers can be more than 6 inches (15cm) across in some species. The plants can get quite large, however, so you need to have enough space for them!
The Bulbophyllum orchid genus is the largest in the Orchidaceae family, with over 1800 species, making it the third largest genus of plants. (Taxonomists will probably eventually split it into several smaller genera, but with so many types of orchids it's a massive undertaking!) They differ widely in appearance, but all have a single leaf emerging from the top of the pseudobulb, flower stems coming from the bottom of the pseudobulb, and a hinged lip designed to tip insects against the column. Many are pollinated by flies, and stink like dung or rotting carcasses, which is a great conversation starter and gives you bragging rights for putting up with it! (They don't all stink, fortunately.) The rhizomes wander all over the place and often branch freely, so it's easy to grow an impressive specimen.