My t most often uses the client, but I think we've both (or maybe just me) slipped up and said patient. I greatly prefer the term client, but I think that because of the way therapy is set up, clients are viewed as having a pathology and therapists as the ones working to help "heal" the pathology in many cases. My pdoc always uses the term patient, even though he is the farthest thing from a traditional doctor I can imagine.