ohhelp
They save you loads of money. That's the best reason.
When we first moved in here the builders had put energy savers in all the fittings with ceiling roses and halogens in the downlighters, all 16 of them (I swapped them before we moved in, site manager thought I was odd).
I've changed 80% of them to led as I can afford them and our electric use has halved. That's partly the halogen oven as well. Even the fridge has an led bulb in it.
An energy saver is probably using 12w, an led uses 4w to provide the same light. New ones are coming out at 2w!. This would be perfect for chandelier type lamps.
After TV's and fridge freezers the lighting is the thing you have on for the longest each day, especially in the winter when it gets dark at 4pm.
I've found LED Hut the best for cashback and discount codes plus you get free delivery over £50. You can usually get 25-30% off plus 20% cashback. I bought some on amazon but they were really poor quality and they refunded me.
You'd need to an audit of what type of bulb you need in every room, add it all to the basket and add a discount code. I think MVCLED25 is active at the moment. You can find discount codes for them quite easily online.
Always order warm white, I put cool white in the utility and it's not nice.