The first time that I saw the .af cctld, I liked it. The now defunct app Famous.aF is the first site that I'd seen use it. It's memorable and AF is becoming more and more mainstream in print. In a growing demographic, it's normal af.

Most people instantly recognize what it abbreviates without actually saying it.
It only works when the name fits with 'as f*ck' when spoken.
For example, Pizza.aF does not work. WTF is pizza as f*ck?
@JayT has a good example, Sexy.aF. It's taken.
Work and are available:
Speedy.aF
Outrageous.aF