What are good cat adoption sites?

It depends on your region, and if you are looking for a young pet or an old one, a rescue or a bred pet. If you are looking for a rescue or an older pet, then go to the RSPCA website for the branch near you and they have a wide selection. If you are looking for an older animal, but maybe not a rescue, then preloved.com is very useful. If you are looking for a bred pet, then it is best to ask around or email a vet near you for recommendations. google maps is helpful for this.

Hope this helps :)