acquaintances: nothing at all
friends: sweetie, sweetheart, honey, babe, baby, darling, sweet pea
very close friends: love, lovely; (adjective) thing - i.e. "Sneaky thing", "Thin Thing", etc.; sir or Lady (noun) [Noted Exception: Paris gets sweetheart, darling, and baby quite often.]
sigoths: nothing at all; occasionally sir or a single moniker like "Angel", "Prince Charming", "Lord Hawk"; very occasionally (adjective) thing - "Shiny Thing"
For whatever reason, I find it unnatural to call the closest people to me the more classical types of endearments (honey, babe, etc.). Possibly because I want to personalize them - but that doesn't explain why I tend to be most comfortable calling my significant others nothing at all. I could go all melodramatic and blather about how such people "transcend mere words"...and maybe they do, after a fashion.
But I know it's caused some friction - people thinking I like them less than I do because I don't have the classical endearments for them. People who don't understand that they've been upgraded rather than downgraded (or vice versa). I explain it to them if they ask, of course, but for the ones who don't ask...sigh.
On the plus side, I like having a "twist" sometimes in my interactions.
Oh, fine - I like being a psychological mindfuck sometimes. Happy?
Quite. [wry grin]