"Better"? That's very subjective. These are both films about what I'd consider unhealthy relationships (in Better than Chocolate Maggie has a screwed up relationship with her family/has a u-haul romance, and in Loving Annabelle there's clearly an abuse of power) so I can't really say there's a "good" or "bad" one.
I found Loving Annabelle to be the more poignant film, and the more masterfully done film, and it's one of my overall favorites.
I think Loving Chocolate is a better introductory film for a fledgling LGBT person, though; Loving Annabelle is just fucked up and painful and much better after you've had your heart broken a few times.