Lockwood.
Like many others have postd, Elmore was my high-quality art introduction to D&D and fantasy in general. By "high-quality art," I mean painted, quasi-realistic material rather than the illustrated pen and ink renderings (whether they be the rather simplistic stuff in the 1ed Monster Manual or the comicbookesque illustrations that dominated 1ed's Monster Manual II). I loved his earlier stuff, especially the work he did with Dragonlance. I continue to admire and respect him (along with others like Keith Parkinson and Clyde Caldwell to name a few), although I think the quality of his work has diminished a little over the recent years.
That said, I do not cling to him as a favored artist because he was one of the first with whom I became familiar. I became familiar with Batman back when Doeg Moench was writing. Should I only appreciate his take on The Dark Knight since I was exposed to the character through Moench above all others? That's ludicrous.
I see Lockwood as the hier-apparent to Elmore. Like Elmore, he has a fantastic command of color and layout. Like Elmore, his images are evocative and have had a major impact in redefining some of the most important creatures in D&D (particularly Dragons). Like Elmore, his images are kinetic and seem to breath. However, I think that Lockwood's images are far more flexible and powerful than Elmore's (more the case since I think Elmore's works have deteriorated drastically since the mid 90s).
Lockwood images are filled with magic. Look at his rendition of the Phoenix in 3ed Monster Manual II; he combines all of the elements associated with birds, fire, and the divine into a powerful, glorious package that many other artists can not achieve. His dragons are phenomenal, combining the best elements of cats, dinosaurs, and reptiles while maintaining a kind of "ecological" realism (the Blue Dragon, for example, has wide feet and very long claws to facilitate walking on and digging through desert sand, large frilled ear "lobes" to reduce heat, and a large nasal horn to help with digging).
I think that Lockwood, along with the likes of Sam Wood and WAR, are the future of fantasy art. But, it's clear that they were influenced, if not necessarily by Elmore, by the same conditions that assisted Elmore. Elmore is like the classical Greek sculptors; Lockwood is like Michaelangelo in the Renaissance.