EMH - David Tennant
He just has to be The Doctor
I cannot ever imagine Doctor Who uttering, "Please state the nature of the medical emergency."
OTOH, Seven might have given him more than "I love you as my teacher and friend, but not in any romantic way."
Daniel Dae Kim was already on Enterprise.. and wasted I might add.
Wasn't he also in a Voyager episode (one of the astronauts from the planet that existed in a different time frame)?