The Death Company Dreadnought, from The Blood Angels of Warhammer 40K (http://www.games-workshop.com/gws/)
I just modeled it for fun. As you can see, it's pretty clean. It's composed by many pieces and I didn't want to expend a huge amount of time making the UV's of every single piece to add some scratches here and there. Maybe some day I retake it to add them and make it look more realistic.
Made and rendered on Softimage XSI with Mental Ray (11/2011)