Boobie and Pookie

This is what my boyfriend and I call each other. It's so cute, they're great nicknames because they they can both be say in a variaty of ways.

Boo - Pook
Booboo - Poopoo (sounds imature, but it's fun to see your partner smile when you call him/her poopoo)
Booba - Pooka

I've even gone so far as to call him booba head.

So depending on the mood, you can call him/her boo/pook...booboo/poopoo, etc. It works great for us.