The more easy classic real time is Simlab Composer 9 Lite (1920 * 1080) Advantage you can reload and mix any 3D format (except moi 3dm) so take OBJ ;)
https://www.simlab-soft.com/3d-products/simlab-composer-lite.aspx


the more funny SketchFab https://sketchfab.com/

The more crazy is MagicaVoxel (maxi 2048 *2048) but you make Voxel art! :) https://ephtracy.github.io
see my posts http://moi3d.com/forum/index.php?webtag=MOI&msg=9096.21

Not sure the more easy Eevee of Blender :) Last Blender 2.80 Beta version is coming last few hours! :) https://builder.blender.org/download/