CFL lighting is extremely efficient - over 80% in fact. However a new contender is getting much brighter and is even more efficient: the LED.
LEDs (light emitting diodes) are commonly used as indicator lights on electronic equipment - for example to tell you the computer is on, or it's accessing the CD drive, etc. Until recently physicists have been unable to make them very bright.
This has now changed and many manufacturers are now making clusters of LEDs as direct replacements for spotlights, such as the 4W version on the right...
Some are also making so-called "cold cathode" lamps. These are essentially the next generation of CFLs with even higher efficiency and a more compact design, but it is very likely that LED lamps will win this race as they can be made even more compact.