...and I cringe whenever someone say that. For sure, I do agree with what it's expressing--at least what I think it is expressing--but not the way it comes out. Regardless of what another has done (positive or negative) we should accord them respect as a human being. So, in this sense, I like and applaud the "hate the sin, respect the sinner." But throwing 'love' in there ruins it for me.
It's simple, really, depending on how we construct our personal identities. But to keep it simple, it seems that who we are consists of how we act and what we believe (though those aren't necessarily exhaustive). And, if we buy into that, it seems difficult to "hate the sin" and "love the sinner" at the same time--just as it'd be difficult to hate cherries but love cherry pie.