Based on her looks, but also her personality.  She had a nice image on Friends, and she is very pretty and natural.  Everyone has different tastes, but you know how those groups work that bestow titles on celebrities.  Jennifer is very wholesome in some ways.

I think those little young sexy curvy tattooed babes walking around this town are the sexiest as far as looks are concerned.  It's when you find out about their drug issues, and a life that has seemingly no direction other than to get high and find the next client that takes away from their looks.

watch this to the end ... answer the second question first  

You might change your mind if she sucked your cock.

They are always more beautiful after they suck your cock.