I don't know if this is an every store thing, regional, local, or what. But, Home Depot has been having a great sale on CREE brand LED replacement clusters for popular household bulbs. This was the purchase from my last visit (Had 2 visits like this thus far):
And this is the add on their website. Most of these are only available IN STORE:
The lights are offered in both hot and cool temps. I think hot is 2700K and cool is around 5000K. For the one bulb style there is also a 40 watt and 60 watt option.