What about Topamax? (oops, nevermind the Topamax, I just reread your post)

I take Abilify, and it has been weight-neutral (after gaining on both Zyprexa and Seroquel), but have to agree with Phil that some of the side-effects can be bothersome--at least for some of us. I've been on it about 8 months, but it took around 4 months to get past the insomnia to the point where I can sleep more than 2-3 hours at a time, and even now need Lunesta to supplement some nights. Other than that, it's been a great mood stabilizer for me.