Voxels, as evidenced by the recent release Teardown. NERF is pretty amazing but isn't real-time like SDF raymarching. Tetrahedral meshes are interesting as well.

One of the best Siggraph papers from last year was Monte Carlo Geometry Processing http://www.cs.cmu.edu/~kmcrane/Projects/MonteCarloGeometryPr.... It doesn't introduce a new representation, but does introduce a new way to render various representations by sampling them in a unified way