I have all LED bulbs in my house, the nice CREE models that look like this. They've all been great, except for the ones I put in my bathroom's four-bulb fixture. One by one, all the bulbs in this fixture--and only this fixture--have been dying. They were purchased at different times so it's probably not a package of lemons that's to blame. What happens is that while the lights are on, every once in a while there is a very brief intermittent flicker. The flicker gradually gets longer until a bulb dies and its LEDs will only produce very, very dim light, even when put in another fixture whose bulb works fine.
I suspect that something it wrong with the fixture itself or its wiring. What could it be?
Here is a picture of the fixture. Only one bulb remains, and I suspect that it will burn out soon, too.
And here's a photo of the base of the dead bulbs: