Here's my rank:
1. Black blades: 2 confirmed so far, although not everyone is a swordsman and only the very top swordsmen get it apparently;
2. Voice of all things: looks like a hereditary thing so far (JoyBoy and the Kozuki Family share it?), only 4 confirmed users so far... yeah, there is the three-eyed tribe, but they seem to be extinct or near extinction currently;
3. Cursed blades: only 4 are known so far, I think they're ultra rare... but again, not everyone is a swordsman, so naturally there aren't a lot of cursed swords;
4. Advanced Conqueror Haki: only the very top conquerors get it apparently, so it's very rare;
5. Advanced Armament Haki Internal Destruction: only Luffy and Rayleigh have shown it so far, but I believe it's less rare than advanced conqueror;
6. Future Sight: only 4 characters have shown it so far, all conquerors, but I believe it's more common than it seems (it could jump to number 4 or 5 if we use the manga's current info);
7. Mythical dfs: there will be possibly more mythical zoans than logias after the confirmation of the Gorosei's (and Imu's) DFs, but I still think that's the rarest type overall, per Kizaru's own words. There are 9 known mythical zoans so far;
8. Logia dfs: 13 known so far, it's the rarest type of DF after the mythical zoans IMO;
9. Awakening: the Jailer Beasts of Impel Down are awakened, so I don't think it's a super rare ability among DF users... it's just above the number 10 because the DFs are somewhat rare per se;
10. Conqueror Haki: the rarest haki of all, only one in 1 million has it, but 1 million isn't that big of a number. Arabasta alone, for example, has 10 million people (SBS Vol. 24). The WG has 170 affiliated nations and there are super populous unaffiliated countries like Wano out there, the One Piece world may have a population of 1 billion or even more.