My 100% hard-surface practice project from years back, featuring the Hulkbuster from Avengers: Age of Ultron.

I used 3ds Max as my main program. No sculpting program was used. I used Unfold 3d to unwrap all the textured parts. Substance Painter was used to add the edge and dust details for the V-Ray materials. V-Ray 3.0 was used to render the scenes. Photoshop was used for final post-processing.