One type fixture that I won't be converting is my 4' fluorescent T8 shop lights. I can buy T8 bulbs in a 12 pack for $30 at Lowes and they are just as efficient as LEDs, and far less expensive.
I've been replacing my older, less efficient T12 shop lights with new LED shop lights from Costco at about $50/ unit though. Mainly because the cheap fixtures themselves have rusted badly over 20 years. In cool white, good for shop work, the light quality is far superior.