In terms of being all-around entertaining: Maryse and Layla. These two are freaking stars. They are decent enough in the ring for what WWE asks for its Divas to do and they are charismatic and sell their characters from entrance to exit.
Maryse should be coming back at the end of October/beginning of November from abdominal hernia surgery. Layla should be back in February/March from her knee injury. The Divas roster will be the better for it.
Of all time, it's impossible to pick out the hottest. I'm not going to pick which one I would wanna fuck the most so I'll just go with Nancy Sullivan just because anybody that would sleep with Kevin Sullivan and Chris Benoit and wife to them she had to have something complex going on upstairs that most woman don't have in this world. God bless her for that.
It's quite sad how little people care about the Diva's wrestling skills. I can't exactly blame them though.
Best diva is... I'm really not sure. Nattie and Beth seem to be the most common answer, but I find them quite average in the ring and only really stick out because most of the diva's suck bollocks in the ring. I have high hopes for Britanni Knight though.