Hello :)
(Mon / Ma) chéri(e)
Mon (petit) cœur
Mon bébé (d'amour)
(Mon) trésor
Mon (petit / bel / tendre) amour,
Mon (petit / bel) ange,
(Mon) chouchou,
Ma biche, (for a woman / girl only)
Ma puce, (for a woman / girl only)
(Mon) chaton,
and Mon (petit) chat
are the terms of endearment that we most commonly use in France, as far as I know. I used all of them, when talking to my sweetheart or to my children.