I second this, as someone who's had shelter kitties her whole life. Shelter cats have just so much love to give and there are so, so many of them without homes. Purebreds will almost always have a home in front of them.
One thing about shelter cats though, is to have some money aside for vet bills, sometimes they come out of the shelter with complications. Mine didn't, I was lucky, but mine were previously declawed by an earlier owner so those cats were special in other regards--declawed cats are cranky.