"An interesting plainness is the most difficult and precious thing to achieve" reads one of the quotes discreetly placed on the walls here. You can get a lot closer to Mies van der Rohe's ideal with these tasteful mid-century pieces, such as Noguchi's paper column lamps and Le Corbusier's steel-frame sofa, plus contemporary furnishings in the same spirit, such as Jesús Gasca's beech "globus" chair. Subway: A, C, E to 14th St. Other location: 142 Wooster St., between Prince and W. Houston Sts., SoHo, PHONE: 212/475-0001; Subway: F, V to Broadway-Lafayette.