These LED lights from Klemko are still my favourite. We've used them on a number of projects, starting with the Cinclus, and now at last get to use them on our own barge.
At 1.2 watts they are more than 15 times as efficient as halogen spotlights, no problems with warmth (degrees C nor light colour) and a hundred times more pleasing to look at.
(at last I've worked out how to put links in my mobile posts - I hope :)