I have used several LED lights, some cheap and some quite expensive, and I don't really like any of them because they tend to have a very narrow beam.
I find that fluorescent lights are better in most situations, especially when I'm working under a dashboard, if there's room for it. Otherwise I use a head strap with a 2 AA Maglite.
I really do not like the old standard incandescent drop lights, but I use this type a lot:
