intelligent, 
bright, brainy (informal), quick, clever, sharp
antonym: stupid
 
keen, 
clever, shrewd, nifty, canny, cool, smooth 
insolent, 
rude, facetious, clever, disrespectful, impertinent (formal), sarcastic 
elegant, 
neat, tidy, stylish, chic, well-dressed, well-groomed, well-turned-out, dapper, 
dashing
antonym: shabby
 
fashionable, 
trendy (informal), chic, glamorous, hip (slang), stylish, voguish, glitzy, ritzy 
(informal), swanky (informal), elegant 
lively, 
brisk, vigorous, energetic, quick, rapid, speedy