Unless you are prepping your cat to enter cat shows, it is a much wiser choice to adopt a cat from the shelter.
- - You are saving lives
- - It costs less
- - There are more choices
- - There are less concerns about health
- - Others
When you visit an animal shelter, you find cats ranging from all ages. If you are looking for a companion whom you will spend a lot of time with, a kitten would be a good choice. If you have a busy schedule, an adult cat is probably a better pick because they are more independent and can be left alone for a longer time.
When a cat reaches its adulthood, his/her personality is usually formed, so it is a lot easier to find the right personality that fits your family with an young or adult cat as oppose to a kitten. Also, most adult cats at the animal shelters have been spayed and neutered, so you don't need to expand that extra effort to see a vet.
Whenever a cat or kitten is rescued, the animal shelter would check their health condition and provide treatment if necessary. All the felines that are up for adoption have been dewormed, vaccinated, micro-chipped and checked for FIV. There is a nominal fee that goes into the adoption process, but that's only a small fraction of the cost you would have to put in should you do everything yourself.
Finally, the most noble reason to adopt a cat is to save lives and provide a home for those underprivileged little furries. Many cats that can't find a home end up being euthanized, even though all the animal shelters hate the idea, they can only do so much to keep the animals there. Your help can literally save lives and bring hope to the rescue efforts.
Here is the directory to the animal shelters by state:
http://www.animalshelter.org/shelters/states.asp
Image: http://en.wikipedia.org/wiki/File:Six_weeks_old_cat_(aka).jpg