The sword could do with an environment map as well to help make it more shiny and sleeker. The handle too perhaps since it seems to be metal.
The helicopter in the second image looks pretty basic, but could make a good game model. A nice texture would greatly improve it.
The third image is very nice, though for some reason the reflections on the black surface seem pixelated! I'm not sure why. Perhaps soft shadows and a bumpmap on the wood could be nice.
The third image is nice. I like the composition! The materials on the speakers could be changed though. They seem very plastic right now and don't really fit in with the style of the rest of the image.
Overall they look nice though. Those are my crits! Of course I enjoyed the images as well.