WordNet sense 1 (characterized by grandeur):

splendid

WordNet sense 2 (having or displaying great dignity or nobility):

majestic

WordNet sense 3 (of behavior that is impressive and ambitious in scale or scope):

grand

WordNet sense 4 (sensational in appearance or thrilling in effect):

dramatic, striking

WordNet sense 5 (impressive in appearance):

imposing, noble, stately

WordNet sense 6 (inspiring awe or admiration or wonder):

awe-inspiring

WordNet sense 7 (producing a strong effect):

telling

WordNet sense 8 (producing or capable of producing an intended result or having a striking effect):

effective, effectual, efficacious