The cats’ favorite place to be pet: Their faces, especially around their lips, chins and cheeks, where they have scent glands. (The researchers did not attempt to pet the cats on their bellies, presumably because they didn’t want to be maimed.)
Interestingly, it doesn't seem to matter what order you pet the parts of your cat. That suggests that cats see petting as akin to grooming, which happens haphazardly between two friendly cats, rather than allo-rubbing, which always goes from tip to tail.
Still, we don’t recommend licking your cat.