The easiest cat to adopt is an adult domestic short-hair in a shelter. Kittens are so cute that adult cats can hardly compete for adoptive families.
To find a friendly cat this is what you do. Go to a shelter such as the Humane Society or other no-kill facility and ask to meet a selection of cats available for adoption. Sit on the floor and see how the cats interact with you. The ones that come over, purring, and want to climb in your lap will be the friendliest ones.
Most cats keep themselves perfectly clean. A few cats have difficulties. In particular these include obese cats who cannot quite reach all the “dirty bits” and long-haired cats who can often tote in extra decorations in their fur. Thus, I suggest a short-haired cat.
The oriental breeds (Siamese, Burmese, etc.) will be the noisiest and the most demanding of your attention. They also love to climb (forget having decent drapes) and are devils for inventing tortures for sleeping humans. However, they are among the longest lived, often making it into their 20s.
In my experience, some orange tabbies are very friendly, but some are so unfriendly that they can be used by the vet to train new staff on handling demons. My cat Julius Seize-Her was one such cat. He was evil. OTOH, my other orange cats range from very friendly (Butch) to slightly aloof (Tiger-Tiger) to exceedingly shy (Milo the Invisible). And yes, orange cats are generally male, while cats with orange and black fur or orange, black and white are generally female (unless they are XXL). It is a sex-linked character.
Our Maine Coon cats have been very loving and friendly, but they do have long hair and shed a lot. My aunt always swore by her tuxedo cats, but I do know that of my brother’s cats, his tuxedo cat Wolfe is quite aloof, while his smoky gray Persians are gluttons for petting and seek out laps constantly.
One breed of cat that is noted for its friendly and almost dog-like character is a newer one called the Ragdoll. One site describes them thusly:
“If you’re looking for an easygoing cat who enjoys being held or sprawled in your lap, the Ragdoll is ideal. These cats enjoy playtime, but are not overly demanding or boisterous. They enjoy trotting along side members of the house and retrieving tossed paper wads. They enjoy activity more at ground level than some breeds who prefer surveying from high perches. Be aware that your Ragdoll may join you in the shower or bathtub as they are highly intrigued by the sound of water. Their super sweet, trusting nature can put them in danger. This breed should never be allowed outdoors without supervision.” http://www.catster.com/breeds/ragdoll
So get over to the closest shelter and start getting to know some of their boarders.