What do you want?
A lot of people have a specific idea of how chickens should look. Do you have any objections to crests, muffs, beards, comb types? Melanisation? Do you just want variety, or do you have a preference for stocky birds or maybe long-legged games or long feathers? Different colored eggs?
What do you want from your flock? Temperament? Egg-laying? Are you willing to deal with broodiness? Are you willing to invest in predator protection, or will your birds need to be fairly self-sufficient?
Budget?
A lot of people have favorite breeds and are willing and able to recommend some beautiful birds, but it really helps to have some general guidelines first.
EDT: Also, if you want friendly chickens, be aware that it's probably easiest to raise them from chicks to be friendly. Adult birds seldom like people much unless they've been raised to it.