There are a few others that haven't been on for a while but would undoubtedly command a lot of attention. San Felix is at #19, JD/m and JD/o are always a challenge for NA, TI9 hasn't been on for a while (although that's one I don't need anywhere myself), VK9X rsees activity every year but rarely anything beyond a vacation-style operation. It's been a while since 9U and 5U have been on as well.
I worked 5U in 2008. According to ClubLog it used to be pretty active until then, and then it suddenly went dark. JD/O I actually worked and confirmed this year.
It's a real shame that some entities aren't active. Banaba supposedly has a permanent population and they are not like P5 or 7O or uninhabited like KP1/5.