in order of efficiancy heres the order
incandescent-worst
quartz or halogen better but still not great efficiancy,,,alot of heat
flourecent -poor color unless expensive color correct lamps are used......poor cold starting,,,,,,only good to 50 degrees unless rated for 0 degrees
mercury vapor /metal halide the beginning of real efficiant lighting.......metal halide has excellent color,,,,can not be turned on and off quickly for room lighting,better for outdoor or warehouse
hi pressure sodium --yellow cast to light but highly efficiant
low pressure sodium-----very very poor color the most efficiant lighting...hard to find as its very difficult to dispose of old lamps..broken lamps in a dumpster can have loose sodium rect with water and start fire,,,