Avon and Servalan, I imagine, wouldn't provoke a great deal of debate as the evidence is there in Deathwatch and Aftermath - although you've provoked a couple of posts neither of which were of the "Isn't Avon cute" variety.
I know my viewpoint is unusual-- there's no disputing Servalan thought Avon was a hottie, but as far as I can see, he's somewhat amazed by her mind, but disgusted by her personally. He only plays charm with her to use her lust for him against her.