From the lighting, it looks like your monitor may be set quite a bit brighter than average. Try reducing your monitor brightness, then adjusting the lighting in your scene.
Alternatively, you could use the unified renderer and increase the gamma when rendering for public viewing:
The table in the fourth image looks like a flattened, SubSurfed cube. Try using SubSurf on other things (like the leg of the table), and increase the Subdiv setting a little - just a little as higher settings will require extraordinary amounts of memory amd can bring your system to a grinding halt (I once set Subdiv to 9, noticed the unresponsiveness, did some quick calculations, slapped my forehead, and reset the computer…)