Most music I listen to was mixed in stereo, then upmixed by my processor into another more immersive format. Stereo sounds flat compared, not bad, but flat, it lacks that "third dimension". For Atmos I think Steve Genewick did an amazing job with the Miles Davis atmos mixes and giles martin did great with the beatles remixes. Revolver sounds sooo good, it is an interesting video he did on the remix process as well. Also I like the tracks that are being dropped mixed natively in atmos, not just remixed. I get an e-mail from dolby about new drops every few weeks.
Giles Martin on the Revolver atmos remix: