It's hard to generalize here since there is so much variation among manufacturers so I'll try to stick mainly to the best examples regardless of manufacturer.
In terms of lumens per watt, the best I've heard so far is an estimated 65 to 70 lm/W from LEDs based on Cree's new 525 nm die (true green). However, the best whites aren't far behind at 55 to 60 lm/W (several manufacturers). The best red-orange is around 53 lm/W, amber about 40, and red about 40 (all from Lumileds). Cree's latest XT-27 blue die should give blue LEDs in the mid 20s.
However, if you're looking at strictly efficiency, meaning percentage of input power which is emitted as light, then I'd say Cree's XT-27 comes in on top at about 42%. If I recall there are also some red LEDs which have similar efficiency numbers but not spectacular lm/W numbers because the eye is less sensitive to red (and blue) light than to orange, amber, and especially green. The green Cree die I mentioned earlier is actually only 14% efficient despite the high lm/W number because the eye is very sensitive to light at that frequency.
As for numbers in the laboratory, we've exceeded 100 lm/W for red-orange and Cree recently announced 100 lm/W 5mm whites.
I hope others can continue where I've left off. This
page should be of further help.