Why are you looking for the best registrar to transfer out of? Why not register your domains at the register you will be transferring to?
Unless you are referring to pushing a domain to another user within the same registrar. If this is the case, Enom, Moniker, GoDaddy, etc are all "good" registrars. Some may require less steps than others, but they all get the job done.
I hope this answers your question.