One of the most important things I tell clients who list properties with me is that they must have clean windows, along with the curtains drawn back and the blinds open to let in the natural light.

This also goes along with having a cleaned house in general, but we all know the three most important things to clean:

1. Kitchen - No one wants to see dirty food in the sink.
2. Bathrooms - No one wants to see dirty anything here.
3. Windows - Finally, everyone wants to see through a window.

I happen to be fortunate enough to have run across a great couple of local college kids who have a window cleaning business here in Denver.  I don't make it a practice to endorse businesses normally, but have been impressed by these guys so far. 

Their info is:

Clear Choice Window Cleaning

Marcus Kirkwood

720-806-4849

They have done very well so far and I plan on using them in the future.  I hope this helps if you have clients that need to have some pros clean there windows (inside and out) and screens.