Some solid-state lasers have pretty high efficiencies, as much as 74% in this case: http://phys.org/news/2011-05-scientists-high-efficiency-cera...

I think I've seen references to 50-60% efficiency for production lasers, though I could be mistaken on that. Given the very low efficiency of lighting systems in general (incandescent bulbs waste 95%+ of input energy, even CFLs and LEDs are in 20-40% range AFAIR), that's very high.