it's more about shape than overall size for me.
girls can be "thick" but have a flat ass, or be on the thinner side but have amazing waist/hips ratio.
i dislike shapeless, whether fat or skinny.
but for what it's worth, i'd take a porker over one of those super-skinny legs & arms/big gut "skinny" types. omfg worst body type EVER. barf.