In my opinion, LEDs are the way of the future for sustainable lighting.
CFLs are great and cheaper but LEDs last much longer and use around 1 Watt compared to CFLs (9 to 14 Watts), Halogens (~ 65 watts), or incandescents (50 to 100+ watts).
For this project, I chose CFLs (still a much better choice than the conventional halogen or incandescent lights) because they cost about half as much as LEDs and I knew that I would be selling our home by the end of the year (I am returning to school this September). Also, LEDs are not quite there yet at least here in Australia.
Nevertheless, check them (LEDs) out!