Well, of course, Mies Van Der Rohe and Walter Gropius, both Bauhaus architects -- Gropius designing the building housing the Bauhaus. The history of that building is, of course, unfortunate. Richard Neutra who designed mostly residential but designed the cyclorama at Gettysburg. Of recent architects in the tradition of the Bauhaus, Richard Meier:
http://www.richardmeier.com/#
He designed the LA Getty Museum.
Niemeyer is one of the biggest names in modern architecture and I think he will always be up at the top of any list. Hope they try to preserve his legacy
by not tearing down buildings. The Neutra Gettsyburg Cyclorama was in jeopardy and there is a public movement to block the destruction. I'm not sure where that is at right now.