You are going to get all kinds of answers based on all kinds of things. I recommend going with the hatchery that is closest to you, and has what you are looking for. Most big hatcheries have been in business a long time because people are mostly satisfied. That being said I personally like and use My Pet Chicken exclusively. So check them all out. Many are sold out this time of year, but some will still have the more common breeds available.
I've ordered from My Pet Chicken 4-5 times. We live in Southern California and usually order 10 or more chicks. We have never had an error in sexing. So far MPC has a 100% accurate sexing record with us. We did have a chick that died a few days after it arrived. We called customer service and they asked that we send them a picture of the chick and they credited our account for our next order.
Keesmom yes ducks but looking for Buffs and he doesn't have that breed. He only has a few duck breeds to pick from. I really like Buffs and Ancona's but not sure which is better I love the looks of both, lol