Luxurious, sumptuous, opulent are comparable when they are applied to things and mean ostentatiously or obviously rich and magnificent.
Something luxurious (see also SENSUOUS ) is exceedingly choice and costly.
Something sumptuous is extravagantly rich, splendid, gorgeous, or luxurious; the word usually suggests a grandeur or magnificence that almost overwhelms the senses.
Something opulent (see also RICH ) flaunts or seems to flaunt its luxuriousness, or luxuriance, and, in some cases costliness.