Could be a few things...
1. If your monitor is old it could be time for a new brighter LCD monitor.
2. Because watching compressed video I would imagine this has a lot to do with the brightness. Infact when DVD's first arrived on the scene - many of them were quite dark and I had to keep adjusting my TV to get a good bright picture. If you are using mpeg or Divx AVI they will be heavily compressed and that is were you are most probably getting dark pictures from.
You could always go back to the traditional methods of a top shelf mag
