He is arguably among the most reliable box office draws in the business. And he has made his career and his fortune by putting his name and his neck out their time and time again. He has never made a superhero film or fantasy tent pole. He has never starred in a sequel. He has made a couple remakes, but both The Taking of Pelham 1 2 3 and The Manchurian Candidate were pretty darn good thrillers. Point being, Denzel Washington makes explicitly old-fashioned movies. He makes sentimental, often true life melodramas (Remember the Titans, John Q), historical dramas (Malcolm X, The Hurricane, American Gangster), politically-topical action pictures (The Siege, Inside Man, Unstoppable) and white-knuckle thrillers (Training Day, Out of Time, Man On Fire, etc). Pretty much every Denzel Washington star vehicle is just that: an original genre picture that features a solid supporting cast and a narrative set squarely on Earth. The closest he's come to out-and-out fantasy, The Book of Eli and Deja Vu, are still character-driven action dramas that don't overdose on special effects or fantasy elements at the expense of the narrative.
His films aren't always good (I'm not a fan of American Gangster or John Q) and they aren't always box office smashes (neither of the two films he directed, Antoine Fisher or The Great Debaters, were financially successful), but they provide the kind of old-fashioned movie-making that is in sadly short supply in this day-and-age. What separates Denzel Washington from the pack of alleged next generation of stars is that he can actually open a movie to $20 million or more all by himself. What separates him from the stars of his generation is that he is still making the kind of movies that made him a sensation in the 1990s. Perhaps one of the reasons that Denzel Washington has maintained his star power for the last 20 years is that he still goes out of his way to make 'the kind of movies they just don't make anymore'.