My lyretail anthias, Bicolor Angels and Bristle tooth tangs (tommi and kole) are have been bullet proof. not only ich resistant, but also very hardy eaters and very long lived...even after a few tank disasters. Same for my pair of Bangi Cardinals. Although it is true that a bristle tooth will some times just randomly die....even when eating well and with no signs if illness. (but when this has happened they have always been at least 2 or 3 years old ((or older depending on the age they were when I got them)).
The Bi-color will eat your acans in short order.
I always keep at least 1 rabbit fish. My two barred was especially a good fish...he would eat out of my hand and got huge (had to sell him because at the time only had a 90g). I have found them to be pretty much bullet proof. (never actually had one die, same thing for my bicolor angel...over 5 years old, been through a lot.....keeps going like an energizer, the lyretail had been through everything the others had...died last week was 5 or 6 years old (could have been older depending on how old it was when I got her).
And my tank raised ocellaris clowns are as mean as any maroon I have ever seen (and huge)...one killed a tang in a few weeks, another actually jumped completely out of my tank while attacking my wife (it was...hilarious). They have take over a 90g and the only thing they will allow to live in there is the bicolor angel I mentioned above. I have never had a tank raised clown die once it got over about 2 inches in size either (but the older they get the meaner they get). I have also seen maroon clowns just go after and try to kill anything and everything.
My Blue throat Trigger (which are supposed to be model citizens and lives in a tank with 3 baby clowns, 4 chromis, a bicolor blenny and an orchid dotty back...immediately killed 3 anthias as soon as they were added). He also will nip at clams if hungry. I have seen them put clown tangs in bad shape in short order!
Also, you might want to add carpet surfers to the list....firefish might be easy (who knows?), ive never been able to keep them in a tank long enough to know...even with a canopy on board.
To date most bullet proof fish: (fish that I basically always had to just sell because they got too big but rarely died).
Rabit fish, Yellow tangs, Hippo Tangs, Clowns, Bristle tooth tangs, my blue thoat went missing and for weeks I though the was dead...found him in the over flow...didn't look like he had lost an oz, so that seems positive. Yellow tail damsels are very hardy and the one I had was not mean at all.