Intersting question, quiet.
My closest blood relatives...there's a lot of love there in the "need-an-organ-here-you-go" sense, but not always a lot of "like". Just very different people. For me it's a love that's based in shared genetics and having more history with them then anyone else.
Somehow though I've managed to build a little "operational" family -- people I have no relation to, but who are as much family to me as my biological one. There's most definitely love that's manifested between us.
The love you feel for someone you fall in love with...well, that's the stuff that poets and writers have been trying to capture into words forever. Not even going to try here
