Belly - both the big, full beach ball belly and a belly with rolls of fat.
Fupa - a big, fat pubic area is sooooooo hot!
Cheeks (face) - chubby cheeks are always sexy.
Breasts - any size. "Smaller" ones in contrast with a huge belly are awesome. The breasts only look small by comparison to the belly when in reality the breasts are D cup and larger.
Butt/wide hips - all the better for holding at the right time. Hand smacking a huge butt makes an amazing sound! Round and bulging butt cheeks are great for holding as well.
Thighs/calves/cankles - skinny legs just don't belong on a BBW. Thick thighs wrapped around me is heavenly.
Shoulders - wide, bare shoulders are erotic. I enjoy the bare shoulder style of clothes.
Arms - thick arms wrapped around me is wonderful.
Fingers - holding pudgy digits and being gripped by them (in various places) makes me very happy.
Lips - kissing full, wet lips is an incredible experience.
Now that I think about these parts, they may not necessarily be listed in the order of most to least favorite. Suffice to say, ALL parts of a BBW body are my favorites!