Fav or fave? As in favourite/favorite.

I can't seem to find anything definitive. What is the correct spelling of this slang term: 'fav/favs' or 'fave/faves?' Phonetically, I would think it would be 'fave/faves.'

Anyone know for sure?

Sorry if this post is inappropriate.

Edit: *hangs head in shame* I'm a bit dense. I don't know why I didn't think of this before hand. Not knowing the correct spelling has been bothering me for months. :P Anyway, I went to Dictionary.com. 'Fav' is not listed as a word, but 'fave' is listed as the slang term for favourite.

Problem solved. Thank you all!