Lighting retrofits can have a strong financial impact in commercial and industrial locations. In homes, upgrading to LED also saves energy, but I believe comfort is the main benefit:
-The bulb lasts 10x longer than incandescent bulbs and 3x longer than CFLs. You can just plug it in and forget about replacements for a long time.
-It releases less heat, which is comfortable if you are sitting close to the lighting fixture.
Most of your residential bill will be composed of heating and cooling expenses (air conditioners, space heaters, water heaters, older refrigerators, etc.). Consider upgrading heating and cooling equipment if you really want to see the electric bill go down.
You might want to check out these three hubs:
Air Conditioning Efficiency:
Resistance Heater VS Heat Pump:
Estimating Payback Period: