Rose.
Domestication is a little harsh, don'tcha think? Let's go with- the infamous Captain Harkness has found something he wants to keep until he has no choice but to let it go.
It does, yeah. I've lost many. You were included in that little spectrum once, but this place has a tendency to bring them all back to me in the end. Besides, now I've got Ianto, you, Doc, my team- I don't need anything else right now.
True. But who else can say they're immortal and this good-looking at the same time?