posh

à la mode (also a la mode), chic, fashionable, in, modish, sharp, sleek, smart, snappy, stylish, swagger, swank (or swanky)

chichi, flossy, haute (also haut), nobby, ritzy, soigné (or soignée)

deluxe, exclusive, high-end, luxe, luxurious, opulent, sumptuous, upmarket, upscale

flamboyant, flashy, glitzy, ostentatious

august, baronial, gallant, glorious, grand, heroic (also heroical), imposing, lavish, magnificent, monumental, noble, ornate, proud, regal, rich, royal, splendid, superb

classy, courtly, elegant, fine, graceful, handsome, majestic, refined, stately, tasteful

artful, genteel, polished, sophisticated

ultrachic, ultracool, ultrahip, ultraposh, ultrasmart, ultrasophisticated