Oh man!! How many times does my post get deleted!!
Well best is a difficult one. First thing to understand is that clowns do not host in coral in the wild. It's unnatural and therefore some corals react badly to the clowns presence. Clowns are very rough when they host and push themselves up against the host.
Elegance Coral is the easiest to get them to host in quickly but it does very very badly being hosted. Usually it dies. So rule that one out.
Goniopora is another favourite of the clowns, and it will normally survive their robustness but goniopora is a very hard coral to keep alive even without te challenge of a clown!
Xenia, and Toadstalls are often known to host clowns.
Hammerhead and Torch are very good hosts and prob the best to recommend, but you will req a very large colony in order for it survive the clowns hosting behaviour.
Overall clown fish will not naturally host a coral so it's hit and miss. They can take years to host things, and sometimes never host corals. It's a wait and see game, there's no way to force it.
It also depends on the type of clown, some clowns host quicker and are less fussy than others.
Sorry I know there's not a definate answer there but unfort there isn't one.
Since I removed my malu the clowns are in my elegance and it seems unaffected so far but research suggests this may bot be the case for much longer.